Mr. Green lives in a small town, but he works in a big city. One day, Mr. Green drives his car out and washes it. When a friend comes and sees the car, he says, "That's a nice car. Is it yours?" "Sometimes," answers Mr. Green. The friend is surprised (惊讶的)." Sometimes?" he asks, "What do you mean?" Mr. Green answers slowly," Well, when there is a party in the town, my daughter, Jane, drives it. When there is a football match, it is my son Joe's turn. When it looks really nice and clean, my wife Linda uses it. And when it needs cleaning, it's mine."