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问题 单项选择题 A1/A2型题

结核分枝杆菌化学组成最显著的特点是含有大量的（）

A.蛋白质

B.脂类

C.多糖

D.RNA

E.磷壁酸

答案

参考答案：B

解析：分枝杆菌属的细菌细胞壁脂质含量较高，约占干重的60%，大量分枝菌酸包围在肽聚糖层之外。

问答题

“一滴水珠可能引发一场火灾”，这是危言耸听还是真知灼见？请从光学的角度谈谈你对这句话的见解。

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写作题

短文写作。

     下面是21世纪报中学生版（21st Century School Edition）刊登的一封读者来信，请你以编辑的身份

给这位中学生写封回信。

Dear editor,

     I spend most of my time studying. I hardly talk to my classmates. I just don't know what to talk about

and how to begin a conversation.

     I feel so lonely. How I wish I had a good friend! Could you give me some advice?

Yours,

John

注意： 1. 回信的内容要包括以下提示要点，适当发挥。

              （1）有自信；（2）多微笑；（3）多交流；（4）帮助同学。

            2. 词数120左右。信的开头已写好，不计入总词数。

Dear John,

     Your problem is a common one among middle school students. Maybe the following advice can help you.

     _____________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________

                                                                                                                                                 Yours,

                                                                                                                                                  Lily
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