问题
选择题
The tourists gathered at________ was once a square, _______ is used as a theme park.
A．where; which
B．what; which
C．which; what
D．that; which
答案
B.
题目分析：游客在曾经是广场现在是主题公园的地方集中。介词at后面的宾语从句缺主语，故第一空填what在从句中作主语；逗号后面是一个非限制性定语从句，故填which. 本题答案选B.