问题补充:
—How about your travel?
—You can hardly imagine what difficulty we have had the vast desert.
A. exploring
B. explored
C. to explore
D. explore
答案:
(答案→)A. exploring
B. explored
C. to explore
D. explore
解析:考查词组:句意:--你的旅行怎样?--你很难想象我们探索广阔的沙漠是多么的不易。
实际上we have had the vast desert.是修饰the difficulty的定语从句,词组 Have difficulty (in) doing sth,在...方面有困难,in可以省略,故选A.