问题补充：
“Where did you find the professor who made the speech yesterday?” “It was in the hall the students often have a meeting.”
A. where
B. which
C. that
D. when
答案：
(答案→)A. where
B. which
C. that
D. when
解析：假若选C，即有 It was in the hall that the students often have a meeting，该句的意思是“学生们通常是在大厅开会”，单独看这一句，无论是其意思还是其语法均未错，但若将其与上文联系起来看，则不通，因为上文的意思是“你是在哪儿找到昨天作报告的那位教授的?”假若将答句改为 It was in the hall that I found the professor，则完全可以。
其实，此题的最佳答案是A，where the students often have a meeting 为定语从句，用以修饰其前的名词 the hall，句意为“是在学生们经常开会的那个大厅(找到教授的)”，这样语意就通顺了。
