A篇
Mum or Brother?
It's Saturday evening. The family have a wonderful dinner. After the dinner, the mother and her son are washing dishes in the kitchen, the father and his daughter are watching TV in the living room. Suddenly there is a crash （打碎） of dishes, and then there's no sound. The girl looks at her father and says, "It must be Mum."
"How do you know it's not your brother?" asks the father.
"She doesn't say anything." says the girl. The father smiles knowingly.
