Why are you looking for Mary in a hurry， John—The boss is wondering where she _____ and how long she ______ there.

How lucky! The tourist stopped at the last moment..—Indeed! One more step and he ________ off the cliff（悬崖）

Nowadays Wechat is____used by people for communicating, sharing, chatting, and so on.

He is such a lazy man _________ nobody wants to work with __________.

While he has got high marks in the college entrance examination, he thinks that it is ______________ satisfactory.