【题目】Last week, we visited the Three Gorges Dam,________is the greatest key water control project in the world at present.
A.thatB.which
C.whatD.where
在线课程【答案】B
【解析】
考查定语从句。句意：上周，我们参观了三峡大坝，这是目前世界上最大的水利枢纽工程。________is the greatest key water control project in the world at present是非限制性定语从句，修饰the Three Gorges Dam，先行词在从句中作主语，指物，应用关系代词which引导该从句。故选B。