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问题 选择题

某有机物的结构式为它在一定条件下能发生的反应有：

①加成           ②水解③酯化      ④氧化

⑤中和                  ⑥消去                ⑦还原

A．①②③④　

B．②③⑤⑥⑦

C．①②③④⑤⑦

D．全部

答案

答案：C

选择题

When you meet many different kinds of difficulties in your study, you’re supposed to    to face them rather than escape from them.

①look for a better way to improve your study

②feel that learning is so boring

③lose heart and lose yourself on other things you like

④ask your parents, teachers or friends to help you

⑤keep a calm heart and never give up

A. ①②④         B. ②③⑤         C. ①④⑤
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单项选择题

胎儿期从母体获得的铁最多的阶段是

A．前3个月
B．前半年
C．后1个月
D．后3个月
E．后半年
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