—Have you worked here since you graduated?—No I at a factory in Beijing for six years.A.

问题补充：

—Have you worked here since you graduated?

—No, I at a factory in Beijing for six years.

A. would work

B. have worked

C. had worked

D. worked

答案：

A. would work

B. have worked

C. had worked

(答案→)D. worked

解析：句意：--自从你毕业就在这儿工作吗？--不是，我在北京的一个工厂工作了6年。从第一句话可知这个人现在在这儿工作，而在北京的6年是过去的六年，所以是过去的动作，用一般过去式，选D。