游泳 游泳是世界流行的竞技运动，有许多不同级别的游泳比赛，包括奥运会级别的。游泳也是一种自己就可以进行的简单运动，可以游着玩玩，也可以锻炼身体。 许多医生和运动员认为游泳是你可以给予自己身体的最好的锻炼之一，因为它几乎同时调动了你所有的主要肌肉群。由于你浮在水面上，不接触任何坚硬的表面，你的关节和骨骼受到比较小的压力，比起其他运动，游泳受伤的可能性比较小。 有许多方法可以推动你成为一个更好的游泳者。如果你想练速度，你可以用表计时，看你游一定的圈数需用时多少。如果你想练耐力，你可以放慢速度，看在不得不休息前你可以游多少圈。游泳是许多青少年最喜欢的运动。一个学生说：“游泳最开心的时候是打破自己记录的时候。是否赢得比赛根本不重要，只要你尽了最大的努力，你就可以笑着离开了。当你在水中时，你会忘记注视着你的人，你所关心的只是到达泳池的另一边，碰到池壁。你可以不顾一切地飞翔。”

Lesson51 Swimming
Swimming is a competitive sport played around the world and on many different levels， including the Olympics． It's also an easy sport to do on your own， both for fun and for exercise．
Many doctors and athletes agree that swimming is one of the best workouts you can give your body， because it works almost on all of your major muscle groups at the same time． Since you're floating in the water and not in contact with any hard surfaces， there's less pressure on your joints and bones．
You're less likely to suffer injuries than with other sports．There are many ways to push yourself and get better as a swimmer． If you're into speed， you can race the clock and see how long it takes you to do a certain number of laps． If you're into endurance， you can slow down and see how many laps you can do before you have to take a rest． Many teenagers like swimming best． One of the students says， “The best part about swimming is when you beat your time． It doesn't even matter if you lose the race as long as you tried your best； you can walk away with a smile on your face． When you're in the water you forget that people may be watching and all you care about is getting to the other side of the pool and touching the wall． You can just let go and fly．”
workout 测验
muscle  肌肉
float  浮
joint  关节
lap 一圈
endurance 耐力