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问题 单项选择题

在爆炸性气体环境中应采取防止爆炸的措施。对区域内易形成和积聚爆炸性气体混合物的地点设置自动测量仪器，当气体或蒸汽浓度接近爆炸下限值的( )时，应能可靠地发出信号或切断电源。

A．50%

B．75%

C．80%

D．40%

答案

参考答案：A

阅读理解

阅读理解。

      Today is Sunday. It's sunny. After breakfast, my father is in the living room. He is reading the newspaper. My mother is in the kitchen. She is washing the bowls and the chopsticks. I'm doing my homework in my room. We are very quiet.

1. How's the weather today?

A. rainy

B. sunny

C. snowy

2. What is my father doing?

A. He is watching TV.

B. He is reading a book.

C. He is reading the newspaper.

3. What is my mother doing now?

A. She is washing the dirty dishes.

B. She is eating breakfast.

C. She is washing the bowls and the chopsticks.
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单项选择题

FK6型加弹机吸丝系统的压缩空气由机外进入，通过吸枪与（）直接相通，将生头时的废丝吸至废丝箱。

A、吸丝风机

B、吸丝管

C、压缩空气系统

D、三角皮带
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