Given the question "Why is the science exam diff icult?" and the answer "We don't know.", write a conversation that might have happened.
W: How were your exams,Mike?M: Not too bad. But I'm sure I made some mistakes in the science paper and maths paper.W: Me, too. The science paper was not easy this time, was it?M: It seems that our new science teacher likes to give us tough exams.W: I have the same feeling. He looks only 25 or so.M: Maybe he hopes to make us pay more attention to his lessons in this way.W: Really?M: Well. I'm only joking.