Read the joke.
In the Train
Two old ladies get into the train at Manchester. They're sitting in the same carriage（车厢）chatting（聊天）．
"Where are you going?" asks one of them.
"To London, to see my son. And you?"
"To Edinburgh, to visit my daughter."
"Oh, really?! How wonderful science is these days," says the first old lady. "We are sitting in one and the same carriage, but are going in opposite（相反的）directions（方向）."