People living in the area where there is a lack of electricity often keep a supply of cand

问题补充：

People living in the area where there is a lack of electricity often keep a supply of candles power failure.

A. in case of

B. once

C. even if

D. in course of

答案：

(答案→)A. in case of

B. once

C. even if

D. in course of

解析：判断逻辑。此处为目的,in case of意思是“万一……”,in course of“在……过程中”,once是连词,用在此处句意不通。