问题
选择题
How I regretted ___the hours in the forest, ___I should have studied hard in the classroom.
A．wasting; when
B．to waste; when
C．wasting; where
D．to waste; where
答案
答案：A
regret doing 后悔做过……，从句上可知第二空是修饰hours 的定语从句。