There are __________ people on the street.[ ]
A. many too
B. many
C. much
D. too much
答案:B
熔断器水平安装相间距离为不小于()。
A、200mm
B、300mm
C、400mm
D、500mm
起重机械的工作机构一般由()大部分组成。
A.3
B.4
C.5
D.6