问题补充：
You can imagine what great trouble I had his address.
A. to find
B. of finding
C. finding
D. about finding
答案：
A. to find
B. of finding
(答案→)C. finding
D. about finding
解析：句意：你很难想象我找到他的地址有多难。做好这题，关键是知道词组 have trouble (difficult) doing sth.做某事有困难．定语从句是I have hadfinding his address，修饰先行词(great trouble)，所以答案是C．
