My mother when I got home yesterday.A. cookedB. cooksC. is cookingD. was cooking

问题补充：

My mother when I got home yesterday.

A. cooked

B. cooks

C. is cooking

D. was cooking

答案：

A. cooked

B. cooks

C. is cooking

(答案→)D. was cooking

解析：句意：昨天当我到家时，我的母亲正在做饭。结合语境可知本句描述的是过去某时正在进行的动作，故用过去进行时态。选D。