小学3 4年级英语单词

小学3 4年级英语单词 3A 1) Animals 动物 1. dog 狗 2. cat 猫 3. monkey 猴 4. tiger 虎 5. panda 熊猫 6. zebra 斑马 7. bird 鸟 8. elephant 大象 2) Fruits 水果 1. apple 苹果 2. orange 橙子，桔子 3. banana 香蕉 4. pear 梨 5. peach 桃子 6. mango 芒果 7. pineapple 菠萝 8. watermelon 西瓜 3) Clothing items 衣物 1. coat 大衣，外套 2. jacket 夹克衫 3. sweater 毛衣 4. blouse 女式衬衫 5. dress 连衣裙 6. skirt 裙子 7. shirt 男式衬衫 8. T-shirt T恤衫 4) Food and drinks 食物和饮料 1. cake 蛋糕 2. hamburger 汉堡 3. egg 鸡蛋 4. ice-cream 冰淇淋 5. coffee 咖啡 6. tea 茶 7. milk 牛奶 8. juice 果汁 5) Colours 颜色 1. red 红色的 2. green 绿色的 3. white 白色的 4. black 黑色的 5. yellow 黄色的 6. blue 蓝色的 7. orange 橙色的 8. brown 棕色的 6) Things for school 文具 1. book 书 2. pen 钢笔 3. pencil 铅笔 4. ball pen 圆珠笔 5. pencil box 铅笔盒 6. pencil sharpener 卷笔刀 7. rubber 橡皮 8. ruler 尺子 7) Vehicles 交通工具 1. car 小汽车 2. bike 自行车 3. bus 公共汽车 ItAAAASA Close to the desired solution was prepared, and then use the reference material (or another material standard) to determine its exact concentration. This determines its exact concentration is called calibration. For example, for the preparation of 0.1mol • L-1HCl standard solution, first with a certain amount of concentrated HCl diluted with water, mixed concentration is about 0.1mol • L-1 in dilute solution, and then use the anhydrous Na2CO3 benchmark solution titration accurately weigh the material until both quantitative response fully, and then consumed in the titration of aqueous solution of HCl volume and quality of anhydrous Na2CO3, calculate the exact concentration of the HCl solution. Most accurate concentrations of the standard solution are determined by calibration of the method. Constant component in the determination of standard solution concentration range of 0.01 mol • L-1-1 mol • L-1, typically according to the components to be tested to select the height of the size of standard solution concentration. In order to improve the accuracy of calibration, calibration should pay attention to the following points: ? determination of calibration should be parallel 3-4, repeated at least three times, and called for determination of the relative deviation is less than 0.2%. ? in order to reduce measurement error, weighing the baseline amount of substance should not be too few, weighing at least 0.2G above; same titration at the end consumption of standard solutions or too small in size, the best is 20mL. C preparation of calibration solutions and use liquor, such as glassware, such as volumetric flasks and pipettes, where necessary, corrected volume, and considering the effect of temperature. D calibration good of standardOperated by stock solution was prepared solution, in principle only be diluted once, if necessary, dilute the secondary. Dilution of too many accumulated error is too large, affect the accuracy of the results. 2. calibration cannot be directly made accurate concentrations of the standard solution, first solution was prepared, and then select the base material calibration. Do the titration with acid and alkali solution, it is usually prepared with about 0.1mol • The concentration of L-1. Of solid acid and alkali solution prepared from original, generally only accurate to 1~2 significant figures, it can be graduated cylinders measuring liquids or solid reagents weigh in the scales, add the solvent (water), graduated cylinder or measuring cup amounts. But in the whole process of calibration solution, everything is very strict and accurate. Weighing standard substances requires the use of analytical balance, accurate to four digits after the decimal point. Volume calibration solution, if it were to participate in the concentration are calculated using volumetric flasks, pipettes, burets accurate operation, not sloppy. (B) the general solution preparation and preservation methods of 1:1 (or 1+1), 1:2 (1+2) volume is expressed as concentration. For example, 1:1 solution of H2SO4, the original concentrated H2SO4 volume 1 volume, mix with 1 volume of water. And as 1:3 HCl, the original volume 1 volume hydrochloric acid and three volumes of water and mix. Preparation of solution, according to the requirements on the accuracy of solution concentration should be determined on the balance at the level of the weighing; record should be written to several significant figures; the prepared solution choose what kind of vessel. That accurate, it should be very strict tolerances can be less stringent. The "quantity" concept 4. plane 飞机 8) Places 地点 1. zoo 动物园 2. park 公园 3. cinema 电影院 4. supermarket 超市 5. the Great Wall 长城 9) People 人物 1. man 男人 2. woman 女人 3. boy 男孩 4. girl 女孩 10) Things in a room 房间物品 1. bed 床 2. table 桌子 3. chair 椅子 4. fridge 冰箱 5. bookcase 书架 6. desk 书桌/办公桌 7. sofa 沙发 8. telephone 电话 9. light 电灯 10. door 门 11. window 窗 12. Walkman 随身听 13. box 盒子 14. basket 篮子 15. TV 电视机 16. tap 水龙头 3B 1 father 父亲 家庭成员 3 3B <3B3> 2 mother 母亲 家庭成员 3 3B <3B3> 3 grandfather 祖父 家庭成员 3 3B <3B3> 4 grandmother 祖母 家庭成员 3 3B <3B3> 5 aunt 姑姑 家庭成员 3 3B <3B3> 6 uncle 叔叔 家庭成员 3 3B <3B3> 7 brother 兄弟 家庭成员 3 3B <3B3> 8 son 儿子 家庭成员 3 3B <3B3> 9 sister 姐妹 家庭成员 3 3B <3B3> 10 daughter 女儿 家庭成员 3 3B <3B3> 11 friend 朋友 人物 3 3B <3B3> 12 cap 帽子(无边) 衣物Clothing items 9 3B <3B9> 13 hat 帽子(有边),礼帽 衣物Clothing items 9 3B <3B9> 14 tie 领带 衣物Clothing items 9 3B <3B9> 15 vest 汗衫,背心 衣物Clothing items 9 3B <3B9> 16 belt 皮带,带子 衣物Clothing items 9 3B <3B9> 17 trousers 裤子,长裤 衣物Clothing items 9 3B <3B9> 18 shoes 鞋子 衣物Clothing items 9 3B <3B9> 19 socks 袜子 衣物Clothing items 9 3B <3B9> 20 storybook 故事书,小说 学习用品Things for school 1 3B <3B1> 21 copybook 习字簿 学习用品Things for school 1 3B <3B1> 22 knife 小刀 学习用品Things for school 1 3B <3B1> 23 tape 磁带,录音带 学习用品Things for school 1 3B <3B1> 24 crayon 蜡笔 学习用品Things for school 1 3B <3B1> 25 school bag 书包 学习用品Things for school 1 3B <3B1> 26 stapler 订书机 学习用品Things for school 1 3B <3B1> 27 clock 时钟 室内物品Things in a room 2 3B <3B2> 28 computer 计算机 室内物品Things in a room 2 3B <3B2> 29 radio 无线电,收音机 室内物品Things in a room 2 3B <3B2> 30 camera 照相机 室内物品Things in a room 2 3B <3B2> 31 watch 手 室内物品Things in a room 2 3B <3B2> 32 toy train 玩具火车 室内物品Things in a room 1 3B <3B1> 33 key 钥匙 室内物品Things 2 3B <3B2> 34 piano 钢琴 乐器Musical instruments 103B <3B10> 35 violin 小提琴 乐器Musical instruments 103B <3B10> 36 guitar 吉它 乐器Musical instruments 103B <3B10> 37 accordion 手风琴 乐器Musical instruments 103B <3B10> 38 football 足球 运动Sports 103B <3B10> 39 basketball] 篮球 运动Sports 103B <3B10> 40 volliyball 排球 运动Sports 103B <3B 10> 41 baseball 棒球 运动Sports 103B <3B10> 42 swimming 游泳 运动Sports 113B <3B11> ItAAAASA Close to the desired solution was prepared, and then use the reference material (or another material standard) to determine its exact concentration. This determines its exact concentration is called calibration. For example, for the preparation of 0.1mol • L-1HCl standard solution, first with a certain amount of concentrated HCl diluted with water, mixed concentration is about 0.1mol • L-1 in dilute solution, and then use the anhydrous Na2CO3 benchmark solution titration accurately weigh the material until both quantitative response fully, and then consumed in the titration of aqueous solution of HCl volume and quality of anhydrous Na2CO3, calculate the exact concentration of the HCl solution. Most accurate concentrations of the standard solution are determined by calibration of the method. Constant component in the determination of standard solution concentration range of 0.01 mol • L-1-1 mol • L-1, typically according to the components to be tested to select the height of the size of standard solution concentration. In order to improve the accuracy of calibration, calibration should pay attention to the following points: ? determination of calibration should be parallel 3-4, repeated at least three times, and called for determination of the relative deviation is less than 0.2%. ? in order to reduce measurement error, weighing the baseline amount of substance should not be too few, weighing at least 0.2G above; same titration at the end consumption of standard solutions or too small in size, the best is 20mL. C preparation of calibration solutions and use liquor, such as glassware, such as volumetric flasks and pipettes, where necessary, corrected volume, and considering the effect of temperature. D calibration good of standardOperated by stock solution was prepared solution, in principle only be diluted once, if necessary, dilute the secondary. Dilution of too many accumulated error is too large, affect the accuracy of the results. 2. calibration cannot be directly made accurate concentrations of the standard solution, first solution was prepared, and then select the base material calibration. Do the titration with acid and alkali solution, it is usually prepared with about 0.1mol • The concentration of L-1. Of solid acid and alkali solution prepared from original, generally only accurate to 1~2 significant figures, it can be graduated cylinders measuring liquids or solid reagents weigh in the scales, add the solvent (water), graduated cylinder or measuring cup amounts. But in the whole process of calibration solution, everything is very strict and accurate. Weighing standard substances requires the use of analytical balance, accurate to four digits after the decimal point. Volume calibration solution, if it were to participate in the concentration are calculated using volumetric flasks, pipettes, burets accurate operation, not sloppy. (B) the general solution preparation and preservation methods of 1:1 (or 1+1), 1:2 (1+2) volume is expressed as concentration. For example, 1:1 solution of H2SO4, the original concentrated H2SO4 volume 1 volume, mix with 1 volume of water. And as 1:3 HCl, the original volume 1 volume hydrochloric acid and three volumes of water and mix. Preparation of solution, according to the requirements on the accuracy of solution concentration should be determined on the balance at the level of the weighing; record should be written to several significant figures; the prepared solution choose what kind of vessel. That accurate, it should be very strict tolerances can be less stringent. The "quantity" concept 43 skating 溜冰 运动Sports 113B <3B11> 44 climbing 爬山 运动Sports 113B <3B11> 45 skiing 滑雪 运动Sports 113B <3B11> 46 fishing 钓鱼 运动Sports 11 3B<3B11> 47 jogging 慢跑 运动Sports 113 B<3B11> 48 running 跑步 运动Sports 113B <3B11> 49 rowwing 划船 运动Sports 113B <3B11> 50 hot dog 热狗 食物和饮料Food and drinks 8 3B <3B8> 51 sandwich 三明治 食物和饮料Food and drinks 8 3B <3B8> 52 pie 馅饼 食物和饮料Food and drinks 8 3B <3B8> 53 bread 面包 食物和饮料Food and drinks 8 3B <3B8> 54 rice 米饭 食物和饮料Food and drinks 8 3B <3B8> 55 soft drinks 饮料 食物和饮料Food and drinks 8 3B <3B8> 56 bar of chocolate 长方块巧克力 食物和饮料Food and drinks 8 3B <3B8> 57 carton of milk 盒装牛奶 食物和饮料Food and drinks 8 3B <3B8> 58 sitting-room 客厅 房间Rooms 7 3B <3B7> 59 dining-room 餐厅 房间Rooms 7 3B <3B7> 60 bedroom 卧室 房间Rooms 7 3B <3B7> 61 bathroom 浴室 房间Rooms 7 3B <3B7> 62 study 书房,学习 房间Rooms 7 3B <3B7> 63 kitchen 厨房 房间Rooms 7 3B <3B7> 64 one 1 数词 4 3B <3B4> 65 two 2 数词 4 3B <3B4> 66 three 3 数词 4 3B <3B4> 67 four 4 数词 4 3B <3B4> 68 five 5 数词 4 3B <3B4> 69 six 6 数词 4 3B <3B4> 70 seven 7 数词 4 3B <3B4> 71 eight 8 数词 4 3B <3B4> 72 nine 9 数词 4 3B <3B4> 73 ten 10 数词 4 3B <3B4> 74 eleven 11 数词 4 3B <3B4> 75 twelve 12 数词 4 3B <3B4> 76 thirteen 13 数词 5 3B <3B5> 77 fourteen 14 数词 5 3B <3B5> 78 fifteen 15 数词 5 3B <3B5> 79 sixteen 16 数词 5 3B <3B5> 80 seventeen 17 数词 5 3B <3B5> 81 eighteen 18 数词 5 3B <3B5> 82 nineteen 19 数词 5 3B <3B5> 83 twenty 20 数词 5 3B <3B5> 4A 1 Mr [用在男子的姓或姓名之前]先生 2 Miss [用在未婚女子的姓或姓名之前]小姐，女士 3 Here you are. <口语>给你。,这就是你(们)所要的东西。 4 notebook 笔记簿 5 copybook 抄写本 6 ruler 尺子 7 sure 当然;有把握的 8 pen 钢笔 9 happy 高兴的，快乐的 10 for 给;为;[表示目标、去向]往;向 11 all right 好;行;不错(短语) 12 card 贺卡;卡片;纸牌 13 teacher 教师 14 come in 进来(短语) 15 come 来 16 that 那;那个 17 you 你;你们 18 your 你的;你们的 19 pencil 铅笔 20 pencil case 铅笔袋(短语) 21 please 请 22 what 什么;多么的 23 is 是(第三人称) 24 yes 是，是的 25 school bag 书包 26 bookmark 书签 27 I 我 28 May I „? 我可以„„吗,(短语) 29 I’ve got 我有;我得到(短语) 30 rubber 橡皮 31 thank 谢谢 32 a, an 一(个，件)(an用于元音音素开头的词前) 33 have 有;得到;做(动作);吃;喝 34 ball pen 圆珠笔(短语) 35 goodbye 再见，再会 36 in 在„„里(内;上);用„„表示 ItAAAASA Close to the desired solution was prepared, and then use the reference material (or another material standard) to determine its exact concentration. This determines its exact concentration is called calibration. For example, for the preparation of 0.1mol • L-1HCl standard solution, first with a certain amount of concentrated HCl diluted with water, mixed concentration is about 0.1mol • L-1 in dilute solution, and then use the anhydrous Na2CO3 benchmark solution titration accurately weigh the material until both quantitative response fully, and then consumed in the titration of aqueous solution of HCl volume and quality of anhydrous Na2CO3, calculate the exact concentration of the HCl solution. Most accurate concentrations of the standard solution are determined by calibration of the method. Constant component in the determination of standard solution concentration range of 0.01 mol • L-1-1 mol • L-1, typically according to the components to be tested to select the height of the size of standard solution concentration. In order to improve the accuracy of calibration, calibration should pay attention to the following points: ? determination of calibration should be parallel 3-4, repeated at least three times, and called for determination of the relative deviation is less than 0.2%. ? in order to reduce measurement error, weighing the baseline amount of substance should not be too few, weighing at least 0.2G above; same titration at the end consumption of standard solutions or too small in size, the best is 20mL. C preparation of calibration solutions and use liquor, such as glassware, such as volumetric flasks and pipettes, where necessary, corrected volume, and considering the effect of temperature. D calibration good of standardOperated by stock solution was prepared solution, in principle only be diluted once, if necessary, dilute the secondary. Dilution of too many accumulated error is too large, affect the accuracy of the results. 2. calibration cannot be directly made accurate concentrations of the standard solution, first solution was prepared, and then select the base material calibration. Do the titration with acid and alkali solution, it is usually prepared with about 0.1mol • The concentration of L-1. Of solid acid and alkali solution prepared from original, generally only accurate to 1~2 significant figures, it can be graduated cylinders measuring liquids or solid reagents weigh in the scales, add the solvent (water), graduated cylinder or measuring cup amounts. But in the whole process of calibration solution, everything is very strict and accurate. Weighing standard substances requires the use of analytical balance, accurate to four digits after the decimal point. Volume calibration solution, if it were to participate in the concentration are calculated using volumetric flasks, pipettes, burets accurate operation, not sloppy. (B) the general solution preparation and preservation methods of 1:1 (or 1+1), 1:2 (1+2) volume is expressed as concentration. For example, 1:1 solution of H2SO4, the original concentrated H2SO4 volume 1 volume, mix with 1 volume of water. And as 1:3 HCl, the original volume 1 volume hydrochloric acid and three volumes of water and mix. Preparation of solution, according to the requirements on the accuracy of solution concentration should be determined on the balance at the level of the weighing; record should be written to several significant figures; the prepared solution choose what kind of vessel. That accurate, it should be very strict tolerances can be less stringent. The "quantity" concept 37 here 在这里;到这里;[用在句首以引起注意或加强语气] 38 morning 早晨，上午 39 good morning [上午见面时用语] 早上好，你(们)好(短语) 40 this 这;这个 41 Happy Teachers’ Day! 祝教师节快乐～(短语) 42 are 是(第二人称) 43 I’d like „(please). [语气婉转地表示请求]我想要„„ 44 hmm [表示迟疑或唤起注意等]呣，嗯 45 ah [表示惊恐、愉快、遗憾等]啊;呀 46 hello [表示问候或唤起注意]喂 47 no 不;不是;没有的 48 can’t 不能;不可以(cannot缩写) 49 guess 猜，猜测 50 How lovely! 多么可爱啊～(短语) 51 dog 狗 52 box 盒子;箱子 53 monkey 猴 54 her 她的 55 look 看，瞧;看上去 56 see 看见;领会 57 have a look 看一看(短语) 58 lovely 可爱的 59 blue 蓝色的;蓝色 60 tiger 老虎 4B 1 new 新的 2 student 学生 3 boy 男孩 4 woman 妇女,女人 5 teacher 教师 6 nurse 护士 7 doctor 医生 8 girl 女孩 9 man 男人 10 our 我们的 11 school 学校 12 Welcome to our school 欢迎到我们学校来 13 who 谁 14 who's=who is 是谁 15 tree 树 16 wow 哇.呀 17 come down 下来 18 climb 攀登,攀爬 19 sir 先生 20 you're = you are 你是 21 right 对的,正确的 22 brother 兄,弟 23 sister 姐,妹 24 white 白色,白色的 25 frienfd 朋友 26 grandfather 祖父,外祖父 27 grandmother 祖母,外祖母 28 father 父亲 29 mother 母亲 30 party 聚会,宴会 31 with 有;具有„„特征 32 eye 眼睛 33 which 哪一个,哪一些 34 in [表示服饰等]穿着 35 Nice to meet you 很高兴认识你 36 hair 头发 37 herd 头,头部 38 ear 耳朵 39 nose 鼻子 40 mouth 嘴;口 41 o'clock „„点钟 42 we 我们 43 we're = we are 我们是 44 be late to 迟到 45 hurry 赶快 46 wrong 错误的 47 waiter (旅馆\饭店等的)男服务员 ItAAAASA Close to the desired solution was prepared, and then use the reference material (or another material standard) to determine its exact concentration. This determines its exact concentration is called calibration. For example, for the preparation of 0.1mol • L-1HCl standard solution, first with a certain amount of concentrated HCl diluted with water, mixed concentration is about 0.1mol • L-1 in dilute solution, and then use the anhydrous Na2CO3 benchmark solution titration accurately weigh the material until both quantitative response fully, and then consumed in the titration of aqueous solution of HCl volume and quality of anhydrous Na2CO3, calculate the exact concentration of the HCl solution. Most accurate concentrations of the standard solution are determined by calibration of the method. Constant component in the determination of standard solution concentration range of 0.01 mol • L-1-1 mol • L-1, typically according to the components to be tested to select the height of the size of standard solution concentration. In order to improve the accuracy of calibration, calibration should pay attention to the following points: ? determination of calibration should be parallel 3-4, repeated at least three times, and called for determination of the relative deviation is less than 0.2%. ? in order to reduce measurement error, weighing the baseline amount of substance should not be too few, weighing at least 0.2G above; same titration at the end consumption of standard solutions or too small in size, the best is 20mL. C preparation of calibration solutions and use liquor, such as glassware, such as volumetric flasks and pipettes, where necessary, corrected volume, and considering the effect of temperature. D calibration good of standardOperated by stock solution was prepared solution, in principle only be diluted once, if necessary, dilute the secondary. Dilution of too many accumulated error is too large, affect the accuracy of the results. 2. calibration cannot be directly made accurate concentrations of the standard solution, first solution was prepared, and then select the base material calibration. Do the titration with acid and alkali solution, it is usually prepared with about 0.1mol • The concentration of L-1. Of solid acid and alkali solution prepared from original, generally only accurate to 1~2 significant figures, it can be graduated cylinders measuring liquids or solid reagents weigh in the scales, add the solvent (water), graduated cylinder or measuring cup amounts. But in the whole process of calibration solution, everything is very strict and accurate. Weighing standard substances requires the use of analytical balance, accurate to four digits after the decimal point. Volume calibration solution, if it were to participate in the concentration are calculated using volumetric flasks, pipettes, burets accurate operation, not sloppy. (B) the general solution preparation and preservation methods of 1:1 (or 1+1), 1:2 (1+2) volume is expressed as concentration. For example, 1:1 solution of H2SO4, the original concentrated H2SO4 volume 1 volume, mix with 1 volume of water. And as 1:3 HCl, the original volume 1 volume hydrochloric acid and three volumes of water and mix. Preparation of solution, according to the requirements on the accuracy of solution concentration should be determined on the balance at the level of the weighing; record should be written to several significant figures; the prepared solution choose what kind of vessel. That accurate, it should be very strict tolerances can be less stringent. The "quantity" concept 48 waitress (旅馆\饭店等的)女服务员 49 drive 司机;驾驶员 50 policeman 警察 51 policewoman 女警察 52 worker 工人 53 cook 炊事员;厨师 54 farmer 农民;农场主 55 job 职业 56 name 名字 57 how old 几岁 58 aren't = are not 不是 59 their 他(们)的;它们的 60 today 今天 61 old 老的 62 about 大约 63 want 要;想要 64 to [动词不定式符号] 65 be 成为;变成 66 how many 多少 67 buy 买 68 some 一些 69 pear 梨 70 grape 葡萄 71 apple 苹果 72 orange 橙子，桔子 73 banana 香蕉 74 peach 桃子 75 fruit 水果 76 kilo 公斤 77 pineapple 菠萝 78 watermelon 西瓜 79 can I help you? 我能为你效劳吗, 80 or 或者 81 yuan 元(人民币单位) 82 great (口语)好极了，很好 83 by 由，被,[表示交通工具等]乘, 坐 84 taxi 出租汽车 85 station 车站 86 hospital 医院 87 train 火车 88 plane 飞机 89 on foot 步行 90 to [表示方向、目的地等]往;到 91 theatre 戏院;剧场 92 how 怎么 93 there 在那里;到那里 94 for [表示目标、去向]往;向 95 supermarket 超级市场 96 library 图书馆 97 airport 机场 98 minibus 小型公共汽车;中客车 99 free 空闲的 100 park 公园 101 Good idea 好主意 102 play 玩;参加(体育活动、比赛) 103 football 足球运动;足球 104 ball 球 105 noodle [复数]面条 106 juice (水果、蔬菜、肉等的)汁;液 107 coffee 咖啡 108 pie 馅饼 109 sweet 糖果 110 tea 茶 111 milk 牛奶 112 snack bar 小吃店;快餐柜/部 113 What would you like? 你要什么, 114 hamburger 汉堡包 115 chocolate 巧克力 116 How about „? <口语>„„怎么样, 117 Something to drink? 要喝些什么吗, 118 Anything else? 还要别的东西吗, 119 a cup of 一(茶)杯 120 how much 多少 ItAAAASA Close to the desired solution was prepared, and then use the reference material (or another material standard) to determine its exact concentration. This determines its exact concentration is called calibration. For example, for the preparation of 0.1mol • L-1HCl standard solution, first with a certain amount of concentrated HCl diluted with water, mixed concentration is about 0.1mol • L-1 in dilute solution, and then use the anhydrous Na2CO3 benchmark solution titration accurately weigh the material until both quantitative response fully, and then consumed in the titration of aqueous solution of HCl volume and quality of anhydrous Na2CO3, calculate the exact concentration of the HCl solution. Most accurate concentrations of the standard solution are determined by calibration of the method. Constant component in the determination of standard solution concentration range of 0.01 mol • L-1-1 mol • L-1, typically according to the components to be tested to select the height of the size of standard solution concentration. In order to improve the accuracy of calibration, calibration should pay attention to the following points: ? determination of calibration should be parallel 3-4, repeated at least three times, and called for determination of the relative deviation is less than 0.2%. ? in order to reduce measurement error, weighing the baseline amount of substance should not be too few, weighing at least 0.2G above; same titration at the end consumption of standard solutions or too small in size, the best is 20mL. C preparation of calibration solutions and use liquor, such as glassware, such as volumetric flasks and pipettes, where necessary, corrected volume, and considering the effect of temperature. D calibration good of standardOperated by stock solution was prepared solution, in principle only be diluted once, if necessary, dilute the secondary. Dilution of too many accumulated error is too large, affect the accuracy of the results. 2. calibration cannot be directly made accurate concentrations of the standard solution, first solution was prepared, and then select the base material calibration. Do the titration with acid and alkali solution, it is usually prepared with about 0.1mol • The concentration of L-1. Of solid acid and alkali solution prepared from original, generally only accurate to 1~2 significant figures, it can be graduated cylinders measuring liquids or solid reagents weigh in the scales, add the solvent (water), graduated cylinder or measuring cup amounts. But in the whole process of calibration solution, everything is very strict and accurate. Weighing standard substances requires the use of analytical balance, accurate to four digits after the decimal point. Volume calibration solution, if it were to participate in the concentration are calculated using volumetric flasks, pipettes, burets accurate operation, not sloppy. (B) the general solution preparation and preservation methods of 1:1 (or 1+1), 1:2 (1+2) volume is expressed as concentration. For example, 1:1 solution of H2SO4, the original concentrated H2SO4 volume 1 volume, mix with 1 volume of water. And as 1:3 HCl, the original volume 1 volume hydrochloric acid and three volumes of water and mix. Preparation of solution, according to the requirements on the accuracy of solution concentration should be determined on the balance at the level of the weighing; record should be written to several significant figures; the prepared solution choose what kind of vessel. That accurate, it should be very strict tolerances can be less stringent. The "quantity" concept 121 pie 馅饼 122 biscuit 饼干 123 basketball 篮球运动;篮球 124 move 动;移动 125 see the doctor 看医生;就诊 126 dear 亲爱的 127 then 那么 128 ice cream 冰淇淋 129 our 我们的 130 classroom 教室 131 blackboard 黑板 132 bookcase 书架;书橱 133 computer 计算机(电脑) 134 chair 椅子 135 picture 图画;照片 136 office 办公室 137 playground 操场 138 open day 开放日 139 bright 明亮的 140 there [与动词be连用表示“有”的意思] 141 there's = there is 表示“有”的意思 142 TV 电视机;电视 143 sometimes 有时 144 watch 观看;留神观察 145 music room 音乐室 146 piano 钢琴 147 near 靠近 148 window 窗 149 songbook 歌本;歌曲集 150 lots of 大量的;许多的 151 T-shirt T恤衫 152 smart 好看的 153 map 地图 154 them [用作宾语]他们;她们;它们 155 China 中国 156 box 盒子;箱子 157 table 桌子 158 bread 面包 159 egg 蛋 160 glass 玻璃杯 161 table 桌子 162 fridge 冰箱 163 knife 刀 164 cup 杯子 165 bottle (盛液体的)狭颈小口瓶 166 rice 米;米饭 167 breakfast 早饭 168 What's for breakfast? 早饭吃什么, 169 cupboard 碗橱;(放食品等的)小橱 170 no 没有的 171 a carton of 一(纸)盒 172 fork 叉 173 plate 盆子;盘子 174 bowl 碗 175 spoon 匙 176 chopsticks [复数]筷子 177 use 使用 178 try 尝试 179 come 来 180 dinner 正餐;主餐(通常是晚餐) ItAAAASA Close to the desired solution was prepared, and then use the reference material (or another material standard) to determine its exact concentration. This determines its exact concentration is called calibration. For example, for the preparation of 0.1mol • L-1HCl standard solution, first with a certain amount of concentrated HCl diluted with water, mixed concentration is about 0.1mol • L-1 in dilute solution, and then use the anhydrous Na2CO3 benchmark solution titration accurately weigh the material until both quantitative response fully, and then consumed in the titration of aqueous solution of HCl volume and quality of anhydrous Na2CO3, calculate the exact concentration of the HCl solution. Most accurate concentrations of the standard solution are determined by calibration of the method. Constant component in the determination of standard solution concentration range of 0.01 mol • L-1-1 mol • L-1, typically according to the components to be tested to select the height of the size of standard solution concentration. In order to improve the accuracy of calibration, calibration should pay attention to the following points: ? determination of calibration should be parallel 3-4, repeated at least three times, and called for determination of the relative deviation is less than 0.2%. ? in order to reduce measurement error, weighing the baseline amount of substance should not be too few, weighing at least 0.2G above; same titration at the end consumption of standard solutions or too small in size, the best is 20mL. C preparation of calibration solutions and use liquor, such as glassware, such as volumetric flasks and pipettes, where necessary, corrected volume, and considering the effect of temperature. D calibration good of standardOperated by stock solution was prepared solution, in principle only be diluted once, if necessary, dilute the secondary. Dilution of too many accumulated error is too large, affect the accuracy of the results. 2. calibration cannot be directly made accurate concentrations of the standard solution, first solution was prepared, and then select the base material calibration. Do the titration with acid and alkali solution, it is usually prepared with about 0.1mol • The concentration of L-1. Of solid acid and alkali solution prepared from original, generally only accurate to 1~2 significant figures, it can be graduated cylinders measuring liquids or solid reagents weigh in the scales, add the solvent (water), graduated cylinder or measuring cup amounts. But in the whole process of calibration solution, everything is very strict and accurate. Weighing standard substances requires the use of analytical balance, accurate to four digits after the decimal point. Volume calibration solution, if it were to participate in the concentration are calculated using volumetric flasks, pipettes, burets accurate operation, not sloppy. (B) the general solution preparation and preservation methods of 1:1 (or 1+1), 1:2 (1+2) volume is expressed as concentration. For example, 1:1 solution of H2SO4, the original concentrated H2SO4 volume 1 volume, mix with 1 volume of water. And as 1:3 HCl, the original volume 1 volume hydrochloric acid and three volumes of water and mix. Preparation of solution, according to the requirements on the accuracy of solution concentration should be determined on the balance at the level of the weighing; record should be written to several significant figures; the prepared solution choose what kind of vessel. That accurate, it should be very strict tolerances can be less stringent. The "quantity" concept