—You didn’t wait for Mr. Black last night, did you?  —No, but we ____. He didn’t return home at all. 

Cars play an important role in modern life, but they_______also cause many problems like air pollution．

It is suggested that a hard line ____ towards terrorists.

— What’s the matter with Peter?— He was seen crying when he was coming out of the office. He ________ by the manager.

In this country it is required that anyone who wants to settle here ______ to pass this kind of test.