Americans use many expressions with the word dog. People in the United States love their dogs and treat them well.
Some people say we live in a dog-eat-dog world. That means many people are competing for the same things, like good jobs. They say if a person wants to be successful he has to work like a dog. This means they have to work very, very hard. Such hard work can make people dog-tired. And, the situation would be even worse if they became sick as a dog.
Still, people say every dog has its day. This means that every person enjoys a successful period during his or her life. To be successful, people often have to learn new skills. Yet, some people say that you can never teach an old dog new tricks(手艺). They believe that older people do not like to learn new things and will not change the way they do things.
Dog expressions are also used to describe the weather. The dog days of summer are the hottest days of the year. A rain in summer may cool the weather. But we do not want it to rain too hard. We do not want it to rain cats and dogs.
If a person without lots of money wants to buy a car, he or she has to ______.

A．treat the dog well	B．live with lots of dogs
C．work like a dog	D．become sick as a dog

The saying you can never teach an old dog new tricks tells us older people ______.

A．have more ways to do things	B．do things more slowly
C．dislike to learn new things	D．know wonderful tricks

Which of the following is NOT true according to this passage?

A．Many dogs are loved and treated well by people in America.

B．“Every dog has its day” means dogs are the most successful animal.

C．“It rains cats and dogs” has the same meaning as “It rains heavily”.

D．There are many expressions with the word dog in English.