Zinc(锌) is one of about 20 elements necessary for good health. It is present in the body in a very small amount but makes it possible for important chemical actions to be carried out in cells. Scientists are just beginning to discover how zinc and other elements work.
　　Researchers first studied zinc as a way to speed recovery. Dr. Waltor Powys formerly with the United States Air Force noted that the laboratory animals recovered faster when some matters were added to their food. One of these matters was zinc. Dr. Powys later tested the zinc treatment on an American airman recovering from medical operations. The airman who received zinc sulphate(硫酸盐) recovered in half of the usual time. Other doctors studied persons who had a number of strange disorders. The doctors learned that all of these problems were caused by lack of zinc in the body. They treated these disorders successfully by giving the patients zinc sulphate.
　　The amount of zinc in the body can be found by examining blood and hair. A lack of this important element is not uncommon among people in both industrial and developing countries. Zinc is found in most high protein(蛋白质) foods such as meat, milk, fish and eggs. It is also found in whole grains. But many people do not eat enough of these food. Food markets should add these elements so that more people could get needed amount of these necessary matters.
1. Which of the following statements is true?
　　A. Scientists found how zinc works a long time ago.
　　B. People need a large amount of zinc to be healthy.
　　C. Zinc allows important chemical actions to take place in cells.
　　D. Zinc must be used in the course of medical operation.
2. One of the results from the study of zinc is that _______.
　　A. there’s only a little zinc in the human body
　　B. food rich in protein contains more zinc
　　C. some physical problems are caused by lack of zinc
　　D. any patient who receives zinc sulphate gets well immediately
3. The best title for the passage may be _______.
A. A New Discovery                               B. Zinc and Health
C. How Zinc Works                              D. Add Zinc to Your Food