—Why did you go back to the shop?—I left my friend there.A. waitingB. to waitC. waitD. wai

问题补充：

—Why did you go back to the shop?

—I left my friend there.

A. waiting

B. to wait

C. wait

D. waits

答案：

(答案→)A. waiting

B. to wait

C. wait

D. waits

解析：考查现在分词做宾语补足语：leave可以做使役动词，表示“使…处于…状态”，可以接宾语+宾语补足语，宾语补足语可以是非谓语动词，my friend和wait是主动关系，用现在分词做宾语补足语，句意：--你为什么回到商店去？--我让朋友一直在那里等了。选A。