模板支架立柱为群柱架时，高宽比不应大于（）。
A.5
B.6
C.4
D.3
参考答案：A
通气短管是（）油罐的专用附件。
A.汽油
B.航煤
C.润滑油
D.原油
You can hardly imagine the difficulty the woman had _____ her children.
A．brought up
B．bring up
C．bringing up
D．to have brought up
