破碎作业一般可分为()。
A.粗碎、中碎、细碎
B.压碎、击碎、磨碎
C.鄂破、锤破、锥破
参考答案:A
—The sick kids in the hospital need our help.
—You're right. So we can't _____ visiting them. [ ]
A. put on
B. put up
C. put off
D. put down
滑模是以液压千斤顶为提升机具,在液压作用下,带动模板沿着混凝土表面向上滑动来成型钢筋混凝土结构的施工方法的总称。( )