吊车梁安装时标高如有负偏差时，可在柱牛腿面与吊车梁下翼缘板之间放入铁垫板，但垫板不得超过（）层
A.三
B.一
C.二
D.四
参考答案：A
一 I'd like to take a week's holiday.
一 _____.We're too busy. [ ]
A. Don't worry
B. Don't mention it
C. Pardon me
D. Forget it
