问题补充：
When he was a little boy，he on the farm.
A. used to working
B. used to work
C. got used to work
D. was used to work
答案：
A. used to working
(答案→)B. used to work
C. got used to work
D. was used to work
解析： used to do sth.意为过去经常做某事。be used to do sth.意为被用来做某事。be/get used to doing sth.习惯于做某事。
