剪刀撑是防止脚手架（）变形的重要杆件和措施。
A、横向
B、纵向
C、专向
参考答案：B
Ann didn't come to my party. Li Lei. [ ]
A. So did
B. So was
C. Neither did
D. Neither was
水泥混凝土属于（）。
A、弹性材料
B、脆性材料
C、塑性材料
D、弹塑性材料
