A Successful Trade
一次成功的交易
It is lunch time. The kids go out to eat. They are excited and hungry. Paul has a ham sandwich. He does not like ham. He wants a tuna sandwich. Sarah has a tuna sandwich. She thinks tuna is smelly. She wants a ham sandwich. Paul and Sarah meet up. They trade their sandwiches. They get what they want.
现在是午餐时间。孩子们出去吃饭。他们既兴奋又饿。保罗有一个火腿三明治。他不喜欢火腿。他想要一份金枪鱼三明治。莎拉有一个金枪鱼三明治