问题
选择题
As we all know, it’s not polite to keep others _________ for a long time.
A．wait
B．waited
C．to wait
D．waiting
答案
答案：D
这里考核keep doing sth和keep sb doing sth结构。
注意：others这里是“别人”的意思。
搜题请搜索小程序“爱下问搜题”
