—Where is that report?

—I brought it to you _______ you were in Mr. Black’s office yesterday.      

A．if

B．because

C．when

D．before

锋面气旋进入锢囚阶段时（）

A.大风和降水区扩大，移速迅速加快

B.大风和降水区扩大，移速大大减慢

C.大风和降水区缩小，移速迅速加快

D.大风和降水区缩小，移速大大减慢