必须要做伸展和热身运动

必须要做伸展和热身运动 　　John： Is it really necessary to stretch and warm up before I go swimming? 游泳前必须要做伸展和热身运动吗? 　　Lily： Yes, it is. If you don't, your legs could cramp up while you are in the water. 是的。如果你不做，游泳时你腿可能会抽筋儿。 　　John： I'm a bit nervous. You guys do have flotation devices, right? 我有点儿紧张了。你们提供救生圈吧? 　　Lily： Yes, we do. In addition, our lifeguards will rescue you if anything happens. 是的，再说如果发生了什么事，我们的救生员也会救你的。 　　John： That's good to know. I'll make sure to be careful. 那就好，我会小心的。