The police are trying to find out the ________ of the man killed in the traffic accident.

I have such a bad cold that I have lost all _____ of smell.

— What should I do before operating the new machine?— You’d better read its ______ first carefully.

In a time of social reform, people’s state of mind tends to keep _______ with the rapid changes of society.

It was a great ______ for him to be pleasant to people he didn’t like.