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问题 多项选择题

针对煤层的开采技术条件和放顶煤开采工艺的特点，必须对（）等制定安全技术措施。

A、防瓦斯、防火

B、防尘、防水

C、采放煤工艺、顶板支护

D、初采和工作面收尾

答案

参考答案：A, B, C, D

阅读理解

Hello! This is my family. I’m David Green. I’m from England. My family is in Beijing. My father and mother work here. My father is a doctor and my mother is a teacher. I have a sister but no brothers. My sister and I are students of a middle school in Beijing. We love China. My home is very nice. My family has a TV and a computer. My room (房间) is big. I have a bed(床), a desk (桌子) and two chairs(椅子) in it. My books are on my desk. I have an MP3 in my bag. There are some pictures on the wall. I like my room and I like these pictures very much.

根据短文内容，判断正(T)误(F)。

小题1:Four people are in David’s family.

小题2:Mr. and Mrs. Green have a son and a daughter.

小题3:David’s father works in a school in Beijing.

小题4:Two chairs and a desk are in David’s room.

小题5:—Is an MP3 on David’s desk?

—No, it isn’

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单项选择题

开关电源的功率调整管工作在开关状态，有体积（）、效率（）、重量轻的优点，可以模块化设计。

A.小；高

B.小；低

C.大；高

D.大；低
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