In the north of China, it has been snowing for weeks on___end, which causes severe damage to crops; it is estimated that the heavy snowfall will come to ____ end next week.

A．/; an

B．the; a

C．a; an

D．an; /

APU关断活门直接控制（）。

A.通入燃烧室的燃油。

B.通入离心电门的气体。

C.通入滑油程序电门的滑油。

D.点火组件的电流。