— You may find the key to the maths problem on page 107.— Ah, it's so simple. I wonder why I __
A. hadn't thought B. haven't thought C. didn't think D. wasn't thinking
题目简介
— You may find the key to the maths problem on page 107.— Ah, it's so simple. I wonder why I __
题目详情
— Ah, it's so simple. I wonder why I _____ of that.
A. hadn't thought
B. haven't thought
C. didn't think
D. wasn't thinking
答案