【题目】They lost their way in the forest, and ________ made matters worse was that night began to fall.
A. that B. it
C. what D. which
在线课程【答案】C
【解析】考查主语从句引导词。句意：他们在森林里迷路了，更糟糕的是天开始黑了。根据连词and可知，本句需要一个引导主语从句的连接词，该词同时还要能在从句里充当主语。that不能在句中作成分；it不能引导主语从句；which意为“哪一个”，不符合本句语境。排除A、B、D三项。故选C。