随着孔密的增加，产率比增加；并且随着孔密的加大，其产率比上升的趋势（）。
A、增加
B、不变
C、减弱
D、不确定
参考答案：C
结合报考的岗位请谈谈“有志者事竞成”。
Mr. Smith is still not so familiar with the city because it was only two months ago, in March, ____ he started
working here. [ ]
A. before
B. when
C. that
D. which
