Heon the farm for twenty years and now he is a teacher.A. has workedB. had workedC. worked

问题补充：

Heon the farm for twenty years and now he is a teacher.

A. has worked

B. had worked

C. worked

D. works

答案：

A. has worked

B. had worked

(答案→)C. worked

D. works

解析：现在完成时表示发生在过去的动作对现在有影响的的事情，而这边对现在已经没有影响了，因为现在是一名老师，所以不用现在完成时；过去完成时表示过去的过去，这里没有过去的动作作为参照的动作，故不用过去完成时；又根据he is a teacher，他现在是老师，故选C。