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问题 单项选择题

用于预防结核病的卡介苗是经反复传代培养而获取的毒力减弱而抗原性保留的变异株，其变异是（）

A.形态与结构变异

B.S-R变异

C.耐药性变异

D.毒力变异

E.生长能力变异

答案

参考答案：D

填空题

单词拼写:  根据首字母或汉语提示写出下列单词。

1. These children love to play t__________ on their English teacher.

2. She is ___________ (擦)the table.

3. It may take a few weeks for you to build up your __________ (体力)again.

4. Don't be particular about food. A b__________ diet is very important for health.

5. Not spitting was __________ (允许)in public.

6.She __________ (尖叫)when she saw a snake approaching her.

7. For Chinese people, Deng Xiaoping T__________ is very important.

8. It __________ (迷惑)me a lot how they could do it without modern technology.

9. The centre of our city is moving _____________. (向东)

10.The __________ (市区的)stores are usually busy during Christmas times.
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单项选择题

美国历史学家沃尔夫·拉弗贝在20世纪70年代说：“一部美国外交史，冷战绝非是其中值得大书特书的光辉篇章。”可以为这一论点提供依据的首选历史事件是（）

A.柏林危机

B.古巴导弹危机

C.越南战争

D.中东战争
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