Mark Twain(马克·吐温)was a great American writer. One day he went to a city by rain. Mark Twain was very busy, so he forgot(忘记)many important(重要的)things.
When he was on the train, the conductor(列车长)asked him for his ticket(票). But he couldn't find(找到)it. The conductor knew(认识)Mark Twain. So she said, "Show me your ticket on your way back. And if you can't find it, it doesn't matter(没关系). "
"Oh, no, "said Mark Twain. "I must find the ticket. Now I don't know where I am going?"
—_________
—Because _________.
—Because _________.