As we all know ,it is not polite to keep others ()for a long time A,wait B,waited C,to wait D,waiting (望解释下原因)

问题描述:

As we all know ,it is not polite to keep others ()for a long time
A,wait B,waited C,to wait D,waiting (望解释下原因)

D
keep sb doing sth 使某人一直做什么事