Reading Comprehension
从下列每篇短文的问题后所给的四个选择项中选出一个最佳答案。

     These days there are pills for just about everything. If you cannot sleep, take a pill. If you are unhappy, take a pill. What if you are overweight and you do not have time to exercise? A new fitness pill may soon be available. Scientists are developing a pill that provides the same benefits as exercise. According to a BBC report, the fitness pill will"build muscle and strength, and even burn fat."
     Researchers found that mice who took these pills could run long distances without previous training. The test mice also ran almost twice as fast. Would you take a pill if it meant you no longer needed to exercise? There is evidence that humans on these pills will also be able to build muscles without exercising. Furthermore, the research suggests that those who exercise and take the fitness pill will be even stronger.
     Some researchers think the fitness pill will be useful in certain situations. People who cannot get out of bed due to ill health may benefit from the drug. Those with too much blood sugar may also benefit. And, this pill may help patients recover from muscle wasting caused by many diseases. Other researchers feel that the average adult might benefit from such a drug. Most adults do not get the 40 minutes of daily exercise doctors recommend. The fitness pill eliminates the need for that time.
     The greatest concern about the fitness pill is in the sports world. Some fear that sportspersons may already be taking this drug to enhance performance. In order to prove to the public that his strength came from hard work and training, Michael Phelps, the world-renowned gold medalist swimmer, voluntarily went through extra drug testing before the 2008 Olympics. Now, all professional sportspersons are required to go through extensive testing for the fitness pill listed as a performance enhancing drug.