— Why didn’t you try your best to get on the subway?

— I tried to, but it started moving ______ I could get on it.

A．before

B．after

C．since

D．if

以下属于进货检验的是（）。

A.装配后的性能试验

B.中间产品入库前的检查

C.物资入库前的检查

D.环境条件试验