下列哪种作业属于悬空作业（）。
A.混凝土浇筑
B.门窗作业
C.登高安装钢梁
D.深基础周边作业
参考答案：A, B
Everything ________ into consideration, he was a good man. [ ]
A. taking
B. taken
C. was taken
D. being taken
测量道岔水平需要用到（）些工机具和仪器。
A.钢板尺
B.轨距尺
C.支距尺
D.轨道测量仪
