问题
选择题
So difficult_____it to acquire a large vocabulary without the help of a teacher that he was close to giving up .
A．he have felt
B．have he felt
C．he did feel
D．did he feel
答案
答案：D
在so...that结构中，若将表示程度的状语“so+adj./adv.”置于句首，主句中需用倒装语序，从句中的时态决定着主句中须用一般过去时。