—What do you think of teaching, Bob?
—I find it fun and challenging. It is a job you are doing something serious but interesting.
A. where
B. which
C. when
D. that
网友回答
(答案→)A. where
B. which
C. when
D. that
解析：A 考察定语从句。本题定语从句的先行词是job，从句的结构是主谓宾结构，定语关系代词在从句中只能充当地点状语，故A正确。