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问题 单项选择题

长期服用肠道灭菌药可引起缺乏的是（）

A.维生素A

B.维生素B

C.维生素K

D.维生素C

E.吡哆醇

答案

参考答案：C

解析：维生素K可由肠道细菌合成，长期服用肠道灭菌药可影响维生素K的合成。

听力题

On the evening of October 7, Li Feng was watching TV while his mother was （1）b      cooking supper in the kitchen. （2）S       the telephone rang. Li Feng （3）q     picked it up to（4）a        the call. It was from a good friend of his（5）m     . She wanted to say “Happy Birthday” to his mother. “Today is Mother’s birthday, but I have already（6）      f_____all about it. Mother gives me a lot of（7）l      and care while I didn’t care for her（8）e    . From now on, I must always（9）r     this, （10）s     my love to her and care for her enough,” Li Feng thought to himself, feeling a little ashamed(惭愧的).
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单项选择题

302型调速器从最低稳定转速升至标定转速规定时间为（）

A、15-18s

B、15-20s

C、18-20s
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