铁路高墩采用滑模施工时,当底层混凝土强度至少达到()MPa时,可继续提升。
A.0.2
B.5
C.1.0
D.2.5
参考答案:A
My sister met him at the Grand Theater yesterday afternoon, so he ______ lecture.
A.mustn’t have attended
B.needn’t have attended
C.couldn’t have attended
D.shouldn’t have attended
在Photoshop中,绘制正方形或正圆形时,选中选择工具后应同时按下()键可实现创建。
A.Ctrl
B.Alt
C.Shift
D.Ctrl+Alt