I used to go to the gym three times a week but I don’t any more.A. work onB. work atC. w

问题补充：

I used to go to the gym three times a week, but I don’t any more.

A. work on

B. work at

C. work out

D. work for

答案：

A. work on

B. work at

(答案→)C. work out

D. work for

解析：考查动词短语：A. work on从事，忙于，B. work at致力于，C. work out锻炼，制定出，结果是，D. work for为…工作，句意：我过去一个星期去三次健身房，现在我不去锻炼了。选C。