I'm sorry i kept you___at the park gate so long.A:wait B:waiting C:to wait D:waited

I'm sorry i kept you___at the park gate so long.A:wait B:waiting C:to wait D:waited
I'm sorry i kept you___at the park gate so long.A:wait B:waiting C:to wait D:waited

I'm sorry i kept you___at the park gate so long.A:wait B:waiting C:to wait D:waited
keep 后只接doing ,没有to do的形式.
keep sb.doing
这就是英语里的语法,外国人平时就这么用.

keep doing sth.一直做某事

kept 是 keep 的过去式
keep doing 固定用法 表示：一直在做某事，keep waiting, 一直在等

keep somebody doing something