Unit 21 Human BiologyThe Olympic Games are not an annual event. According to the routine, it is held every four years.All athletes feel privileged to take part in the games. They come here not only to seek gold medals but also to challenge themselves. It's true that to win a gold medal means both a large fortune and a great fame.It goes without saying that every athlete aims to get the best results at all costs. However, some athletes turn to doping, which is absolutely prohibited. As is known to all, doping violates fundamental sports spirit and contradicts people's faith in fair play. So the act of doping cannot be tolerated, and if an athlete wants to achieve success by abusing drugs, his efforts will surely be in vain.So every athlete must obey all the rules unconditionally. In no circumstances should they violate them. And the best performanceenhancing way is not pills but systematic training and hard work.When it comes to winning in sports, teamwork is very important. Meanwhile, every athlete must have faith in himself or herself.Among all Olympic events, track and field events are most exciting and attractive, especially dash, which is a competition of speed. Marathon is also very attractive, which is a test of both physical strength and perseverance.奥运会不是一年一次的赛事。根据惯例，它每四年举办一次。能参加这项体育盛会，所有的运动员都感到非常荣幸。他们不但是为了追求金牌，而且是为了挑战自我。不可否认，获得奥运会金牌既意味着一大笔财富，也意味着很高的知名度。不言而喻，每位运动员都想不惜一切代价取得最好的成绩。然而，有些运动员采取服用兴奋剂的下策，这是绝对禁止的。众所周知，服用兴奋剂既违背体育的根本精神，又违背人们对公平竞争的信仰。因此服用兴奋剂的做法是绝对不能容忍的，如果一位运动员想通过滥用药物来获得成功，他的努力必将是徒劳的。所以，每位运动员都...
