【题目】Young people are seeking excitement and challenges, and going where big companies are is ____ leads to so many old people being left alone in villages.
A. where B. when
C. what D. who
在线课程【答案】C
【解析】
考查名词性从句。句意：年轻人寻找刺激和挑战，去了大公司所在的地方是导致许多老人独自留在农村的原因。此处为表语从句，从句中缺少主语，应使用what引导。故C选项正确。