采用井点降水，应持续到（）为止。
A.基坑开挖完毕
B.基础施工完毕
C.土方回填后
D.通过计算确定
参考答案：C
Ever since the financial crisis ________, many workers _______from their jobs.
A．broke out; were laid off
B．has broken out; were laid off
C．had broken out; had been laid off
D．broke out; have been laid off
架梁法施工
