Does everyone know what to do if a fire ?A. is broken upB. breaks upC. is broken outD. bre

问题补充：

Does everyone know what to do if a fire ?

A. is broken up

B. breaks up

C. is broken out

D. breaks out

答案：

A. is broken up

B. breaks up

C. is broken out

(答案→)D. breaks out

解析：考查时态及语态.当主句为一般现在时态时,从句用一般现在时态.句子fire是爆发的主体,故用主动语态,选D.