What great trouble the boy had his father to quit smoking!
A. persuaded
B. persuade
C. to persuade
D. persuading
网友回答
A. persuaded
B. persuade
C. to persuade
(答案→)D. persuading
解析：考查固定结构。固定结构:have some trouble (in) doing sth做某事有困难；本题只是把trouble提前，后面使用定语从句，关系代词知道trouble作为had的宾语，那么横线上所填应该是D。故D正确。