We had to be patient because it ________ some time ________ we got the full results.

A．has been；since

B．had been；until

C．was；after

D．would be；before

运送硝化甘油类炸药以外的其他炸药时，炸药箱堆放的高度不得超过罐笼高度的（）。

A.2/3

B.1/2

C.3/4

D.3/1