As to keeping a pet dog,I am for it.Why?Because pet dog is so cute and they are so pure,not just like some sophisticated adults.When you come back home,the dog will run so happily to you,and sometimes even lick you.So that is why dog can make people happy when they have some sad feelings.Futhurmore,dogs are always known as freinds of human beings.Sometimes,you have unhappy things,when you talk to him,he seems like that he can understand.So,I think keeping a dog is something good.