I'm sorry I have kept you ______ so long.是waiting还是to wait?

I'm sorry I have kept you ______ so long.是waiting还是to wait?
I'm sorry I have kept you ______ so long.
是waiting还是to wait?

I'm sorry I have kept you ______ so long.是waiting还是to wait?
waiting~按照语义整个句子的意思是很抱歉,让你久等了,由于等待这个动作是持续的,所以选择现在进行时,另外,英语固定结构keep somebody doing~

waiting
keep sb. doing sth.

waiting
是让某人持续作某事

waiting因为keep sb. doing sth

waiting
因为你别人一直等到你出现

waiting keep sb doing sth. 让某人一直做某事

waiting 表示时间的延续。