When electrical equipment is involved in a fire，the stream of dry chemicals should be（）.

A.aimed at the source of the flames

B.fogged above the equipment

C.shot off a flat surface onto the flames

D.used to shield against electrical shock

暴雨时开车不小心进入积水深处，汽车熄火，车窗和车门无法打开，眼见积水还在迅速上涨，此时应该（）

A、等待积水退去

B、打手机报警，等待救援

C、努力自救，用铁锤或汽车头枕敲碎侧面玻璃逃生