This is the problem _______ you should pay attention.A.to which不明为什么用to which
问题描述：
This is the problem _______ you should pay attention.A.to which
不明为什么用to which
答
where
答
pay attention to 固定词组。
which 指代前面的 problem
答
考的是宾语从句，还有pay attention to 的固定搭配
答
to which
pay attention to把to提前了
答
the problem后面接了一个宾语从句
这个从句完整的是
you should pay attention to the problem
有两种方法变成从句
the problem to which you should pay attention
the problem which you should pay attention to