题目内容：

what do you think of teaching, Bob? ——I find it fun and challenging. It is a job( ) you are doing
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. when
为什么答案选A,我选B,可以表示当你做的时候,觉得有点难但很有趣

优质解答

它是个定语从句,因为从句中主语和宾语都有.所以先行词job 在从句中做状语指的是 in this job.在这种工作中,你做着严肃而又有趣的事,把 先行词job 放回到从句中就是：you are doing something serious but intereting in the job.
要注意的是不能认为where 指地点,它还可以指情况,形势,例子,等,只要是做状语,而先行词又不是the reason (这时关系词用why,),时间（用when),其他的都可用where 引导定语从句.