about dogs 帮忙将下文中的“?” 按顺序填出来 最好是原文

Americans use many expressions with the word dog.People in the United States love their dogs and treat them well.They take their dogs for walks,let them play outside and give them good food and medical care.However,dogs without owners to care for them lead a different kind of life.The expression,to lead a dog's life,describes a person who has an unhappy （existence）.
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 that to be successful,a person 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.They believe that older people do not like to learn new things and will not change the way they do things.
Some people are compared to dogs in bad ways.People who are unkind or uncaring can be described （as meaner than a junkyard ）dog.（ Junkyard ）dogs live in places where people throw away things they do not want.（ Mean） dogs are often used to guard this property.They bark or attack people who try to enter the（ property）.However,sometimes a person who appears to be mean and threatening is really not so bad.We say his bark is worse than his bite.
A junkyard is not a fun place for a dog.Many dogs in the United States sleep in safe little houses near their owners' home.These doghouses provide shelter.Yet they can be cold and lonely in the winter.
Husbands and wives use this doghouse term when they are angry at each other.For example,a woman might get angry at her husband for coming home late or forgetting their wedding anniversary.She might tell him that he is in the doghouse.She may not treat him nicely until he apologizes.However,the husband may decide that it is best to leave things alone and not create more problems.He might decide to let sleeping dogs lie.
Dog expressions also are used to describe the weather.The dog days of summer are the hottest days of the year.A rainstorm may cool the weather.But we do not want it to rain too hard.We do not want it to rain cats and dogs.