“Sam,” says Sam’s father, “put on your cap and let’s go for a walk.”
    Sam is happy. He likes to go out with his father. He puts on his cap and coat and says “Father, I am ready.” Sam and his father go out into the street. Suddenly they see a big black dog. The dog begins to bark. Sam is afraid of the dog. He wants to run home. His father says, “Don’t be afraid, Sam. Don’t you know the proverb(谚语):‘A barking dog does not bite’?”
    “Oh, yes,” says Sam, “I know the proverb, but does the dog know the proverb?”（ 我知道这个谚语，问题是这狗知不知道呢？）