由我国主要地震带的分布图可知，我国约有（）多条地震带，地震分布很广。
A.10
B.20
C.30
D.40
参考答案：B
数字仪表中通常采用的A/D转换器为（）类型。
I strongly recommend that the information______ in my report____to our headmaster without delay.
A．to be referred to; to be e-mailed
B．referring to; e-mail
C．referred to; be e-mailed
D．being referred to; being e-mailed
