Mary as a secretary in this pany for twenty years and now she stays at home taking care of her own garden.
A. has served
B. had served
C. is serving
D. served
网友回答
A. has served
B. had served
C. is serving
(答案→)D. served
解析：D 句意：Mary在这家公司当了20年的秘书，现在她待在家里照看她的花园。“Mary在公司当秘书”是发生在过去的事情，因此用一般过去时，注意Mary现在不在公司当秘书了，因此不能用现在完成时。