动火分析合格标准按以下原则确定：可燃气体爆炸下限小于10%、大_爱下问搜题

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问题单项选择题

动火分析合格标准按以下原则确定：可燃气体爆炸下限小于10%、大于等于4%时，可燃气体含量小于等于（）%时，动火分析为合格。

A、1

B、10

C、4

D、0.5

答案

参考答案：D

完形填空

完形填空。

     I am an American girl.    1    name is Betty. I am fourteen years old. I    2 a Chinese friend.    3
name is Zhang Hong. She is fourteen,    4    . Zhang Hong and I    5    in Class 2, Grade 7. We have
lunch at school. After lunch we play games    6    the playground (操场) then    7 books in the library.
Our school is very    8   . There are many students    9 our school. We   10   our teachers and school
very much.

( )1. A. His
( )2. A. is
( )3. A. My
( )4. A. too
( )5. A. be
( )6. A. of
( )7. A. read
( )8. A. small
( )9. A. by
( )10. A. like

B. Her
B. knows
B. Her
B. also
B. am
B. on
B. look
B. long
B. in
B. have

C. My
C. have (有)
C. His
C. either
C. are
C. with
C. see
C. big
C. on
C. know

单项选择题

一只11瓦节能灯的照明效果，顶得上（）瓦普通灯泡，而且每分钟都比普通灯泡节能80%。

A.25

B.40

C.60

D.100