It is a shopping mall has been built in used to be a school.
A. which; where
B. that; what
C. which; that
D. that; where
网友回答
A. which; where
(答案→)B. that; what
C. which; that
D. that; where
解析：考查强调句型和宾语从句。第一空that与it is构成强调句型，强调主语a shopping mall；第二空what引导宾语从句what used to be a school，在句中做主语。句意：一个购物中心建在了过去曾经是一所学校的地方。故B正确。