Jeff has a pet. It's a dog. It is white. Jeff likes it very much. He thinks the dog is very smart. It can play ball games and it can buy newspapers for Jeff. Every morning, Jeff puts one yuan into the dog's mouth and it goes to the shop to buy newspapers for Jeff.
Jeff has a good friend Mark. Jeff tells Mark about his smart dog. Mark doesn't believe it. Today, Mark comes to see Jeff in the morning. Jeff is playing with his dog. Mark says, "I will give your dog money. I don't think it can buy newspapers." "Have a try." says Jeff.
Then Mark puts money into the dog's mouth and the dog walks out. After ten minutes, the dog doesn't come back. After an hour, the dog still doesn't come back.
"How much money do you give the dog?" asks Jeff.
"Five yuan."
"Well, if it has five yuan, it will go to the movies." says Jeff.