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问题 单项选择题

抗体初次应答的特点是

A．抗体以IgG类为主

B．抗体亲和力较高

C．抗体浓度达到平台期所需时间较短

D．抗体生成"倍增时间"较长

E．抗体产生潜伏期较短

答案

参考答案：D

选择题

— Do you know about the Japanese nuclear crisis(核危机)?

— Yes. I know           .

A．how are they dealing with it

B．what it has caused

C．how terrible was it

D．how long will it last
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选择题

The policeman asked the child ____ so that he could take him home. [ ]

A. where did he live

B. where he lived

C. how did he live

D. how he lived

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