Listen to the tape and fill in the blanks according to what you have heard. Jim: Hi, Susan, may I ask you a question? Susan: OK, sure! Jim: Do you know which is 1 __ part of our human body? Susan: Well, it’s a hard question. Let me see, eh... Jim: Just guess! Susan: I think it must be 2 __ . Am I right? Jim: No, I don’t think so. Susan: Why, our brain is very important. If it doesn’t work or can’t 3 __ , we won’t be a 4 __ . Jim: True, but what about your eyes? Without eyes, we can’t see anything. We will live in 5 __ . Aren’t they important? Susan: I’m afraid I don’t agree with you. They are important, but they are not the most important part! Jim: Well, what about 6 __ ? If we didn’t have a good heart, what’s the meaning of our life? Susan: Well, yes, hearts are also important, er ...