题目

Some years ago the captain of a ship was very interested   16    medicine. He always   17        medical books to sea and liked to talk about different diseases. One day a lazy sailor on his ship pretended   18   ill. He lay on his bunk (铺位) and groaned (呻吟) as if he    19   very sick. The captain came to see him and was very pleased to have a patient to   20   . He told the man to rest for a few days and  21   the other sailors do his work. Three days later  22       sailor pretended that he had  23   with his chest.     24    th下列物质中在人体血液中含量最少的是A.蛋白质B.葡萄糖C.无机盐D.激素