My parents live in a small village.They always keep candles in the house there is a power cut.
A. if
B. unless
C. in case
D. so that
网友回答
A. if
B. unless
(答案→)C. in case
D. so that
解析：根据句意可知留蜡烛在家里是为了以防万一停电。in case意为“以防万一”；if 引导条件状语从句,意为“如果”；unless引导让步状语从句,意为“如果不”；so that引导目的状语从句,意为“为了”。