下面不是造成充填中支架移位的原因是
A．包埋的石膏强度不够B．未包牢或包埋有倒凹C．填塞时塑料过硬D．充填塑料不足E．支架本身焊接不牢
参考答案：D
As the road to the airport is under reconstruction, we'd better ________ early to avoid the traffic jam.
A．pay off
B．set off
C．put off
D．take off
烟花爆竹工厂1.3级厂房的人均使用面积最小为（）㎡。
A、3.5
B、4.0
C、4.5
