目前，我国线路作业机械化程度约为（）。
A.10％
B.20％
C.30％
D.40％
参考答案：D
You can have a pen, _____him, he can’t have one.[ ]
A. as of
B. as for
C. as about
D. as in
试述商务谈判中的还价技巧。
