The driver was at ______ loss when ______ word came that he was forbidden to drive for speeding. [ ]

A. a; / 

B. /; /

C. the; the  

D. a; the

运行中发现电压表回零或指示不正常时，应首先检查电压表是否损坏，然后在检查熔断器熔丝是否熔断。