问题 单项选择题

具有特别强的致热活性,是内毒素的主要成分( )

A.磷脂

B.脂多糖

C.蛋白质

D.淀粉

E.葡萄糖

答案

参考答案:B

解析:注解:热原是由微生物产生的类毒素,类毒素是由磷脂、脂多糖和蛋白质组成的高分子复合物,存在于细菌的细胞膜和固体膜之间,其中脂多糖是内毒素的主要成分,具有特别强的致热活性。

阅读理解

根据短文内容,选择最佳答案。

     One day an Indian went to his doctor. The doctor looked him over and said, "Medicine ( 药)won't

  help you. You must have a good rest. Go to a quiet place for a month, go to bed early, drink milk, walk

  a lot, and smoke( 吸) only one cigar ( 烟) a day. "

     A month later the Indian came to see the doctor again.  "How are you?"said the doctor, "I'm glad to

 see you again. You look much younger. " "Oh, doctor, I feel quite well now!"said the Indian.  "I had a

  good rest. I went to bed early, I drank a lot of milk. I walked a lot . You certainly helped me. But you

 told me to smoke one cigar a day, and that one cigar a day almost killed (杀死) me at first. It was no joke

  to begin smoking at my age. "

1. One day an Indian _____.

    A. wasn't feeling well    

    B. went to see a friend    

    C. felt very tired  

    D. went to his doctor and helped him

2. His doctor _____.

    A. could not help him  

    B. was good to him    

    C. told him what to do  

    D.  was glad to see him

3. When the Indian came to see the doctor again _____.

    A. the Indian was younger    

    B. the doctor was not free    

    C. the Indian  felt quite well    

    D. the doctor looked him over

4. The Indian told the doctor _____.

    A. he liked doing all those things    

    B. he almost killed him    

    C. to smoke one cigar a day  

    D. one cigar a day was very difficult at the beginning

5. From this story we can guess _____.

    A. the Indian was not a young man    

    B. the doctor was very interesting   

    C. the doctor was a good one    

    D. the Indian didn't smoke at first

单项选择题 A3/A4型题