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问题 选择题

下列有关化学基本概念的判断依据正确的是（　　）

A．强弱电解质：溶液的导电能力大小

B．共价化合物：是否含有共价键

C．氧化还原反应：元素化合价是否变化

D．金属或非金属：晶体是否能够导电

答案

答案：C

单项选择题

乳腺导管不包括（）。

A.小叶内导管

B.总导管

C.小叶间导管

D.乳腺腺泡

E.以上均不是
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填空题

括号中所给动词的正确形式填空。

1. It's five o'clock. The students ________ (play) football on the playground.

2. You _______ (not pass) the exam if you don't work hard enough.

3. The baby is sleeping. Could you please stop ________ (make) so much noise?

4. This machine ________ (use) for cleaning the house.

5. The man spoke very slowly. He wanted me ________ (understand) what he said.

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