问题
选择题
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
A
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。