Allen followed his customer across the yard and stood on the step of the house two shoppi

问题补充：

Allen followed his customer across the yard and stood on the step of the house, two shopping bags.

A. lifted

B. having lifted

C. to lift

D. lifting

答案：

A. lifted

B. having lifted

C. to lift

(答案→)D. lifting

解析：考查非谓语动词。lifting 在这里做伴随状语，动作与位于动词同时发生。句意：艾伦跟着他的顾客穿过院子，站在房子的台阶上，拎着两个购物袋。所以选D。