平行投影法包括:正投影和( )。
A.水平投影;
B.侧投影;
C.中心投影;
D.斜投影
参考答案:D
At no time _____ in the meeting-room. [ ]
A. is smoking permitted
B. smoking is permitted
C. smoking is it permitted
D. does smoking permit
高处作业人员应佩带()。