Many memories of old times were ______ by the conversation we had during the get-together.

We were sad to learn that several students were          by a car yesterday.  

．Elephants, which are the largest mammals on the earth, have almost no natural enemies ______ human beings.

--How are your business goes wrong? ---But I have done all that is    by law.

He slowed the bleeding by      pressure to the wounds until the ambulance arrived．