David: Welcome to Dogs’ World. What’s your dog’s name, Officer White?

Officer White: He’s called Billy. 

David: What kind of work does Billy do?

Officer White: He works at the airport. He smells people’s bags and tries to find dangerous things. 

David: Billy does a great job. Jane, you have your pet dog Suzy with you today. I heard that she helped you a lot last month. 

Jane: Yes. I was very sick and I couldn’t walk around. She turned on and off the lights, brought me things, and even answered the door!

David: What a clever dog! My dog only knows how to eat and sleep! Miss Brown, your dog Winnie is very famous. She appears on TV very often. 

Miss Brown: Yes, but she can’t act when she’s hungry or tired. 

David: Just like me! I can’t work when I’m hungry or tired.