A、Because it’s thicker and more costly than the body. B、Because the consumers find small lids easy to open. C、Because small lids

M: Hi, Jessica.
   W: Oh hi, Bob.
   M: I’m glad I’ve bumped into you. I’ve just found a great idea for the presentation we’ve got to do for Dr. Taylor next month.
   W: What, the one on everyday objects?
   M: Yes. Read this article. It’s really interesting.
   W: The aluminum coke can?
   M: You know ... coca cola cans, soft drink cans. Look, let’s sit down here. Have you got a minute?
   W: Sure. So you think we can get a presentation out of this article?
   M: I’m sure we can. First of all, we can provide some interesting facts about the aluminum cans that we drink out of every day. It says that in the US they produce 300 million aluminum drink cans each day.
   W: Wow! 300 million!
   M: Exactly. And they say that the manufacturers of these cans exercise as much attention and precision in producing them as aircraft manufacturers do when they make the wing of an aircraft!
   W: Really! Let’s have a look.
   M: They’re trying to produce the perfect can—as thin but as strong as possible.
   W: Mmm ... it’s interesting ... today’s can weighs about 0.48 ounces: thinner than two pieces of paper ... from what this magazine says.
   M: Yeah, and yet it can take a lot of weight.
   W: More than 90 pounds of pressure per square inch—three times the pressure of a car tire. OK, I agree, it’s a good topic.
   M: What I thought was that we could do a large picture of a coke can and label it and then talk about the different parts. Look, I’ve done a rough picture here.
   W: OK, so where shall we start?
   M: Well, the lid is complicated. Let’s start with the body first. I’ll do a line from the centre of the can...like this... and label it "body". What does it say?
   W: It’s made of aluminum, of course, and it’s thicker at the bottom.
   M: Right, so that it can take all that pressure.
   W: And then I think you should draw another line from the body for the label.
   M: Yes, because it’s so attractively decorated.
   W: Good... and then there’s the base.
   M: Yes, it says the bottom of the can is shaped like a dome so that it can resist the internal pressure.
   W: That’s interesting. I didn’t know that.
   M: Nor did I. OK, so going up to the lid... there are several things we can label here. There’s the rim around the edge which seals the can.
   W: Got that. I think we should label the lid itself and say that it constitutes twenty-five percent of the total weight.
   M: Twenty-five percent... so it’s stronger than the body of the can.
   W: So to save money, manufacturers make it smaller than the rest of the can!
   M: Didn’t know that, either. Well, I think we’ve got the basis of a really interesting presentation. Let’s go and photocopy the article.
   W: Fine. I’ll take it home and study it some more.
   This is the end of Conversation One. Questions I to 5 are based on Conversation One.
   Question 1
   What are they preparing?
   (pause: 10 seconds)
   Question 2
   What is a perfect can like?
   (pause: 10 seconds)
   Question 3
   What are they going to begin with when introducing the can?
   (pause: 10 seconds)
   Question 4
   What is the bottom of a can like?
   (pause: 10 seconds)
   Question5
   Why is the lid so small?
   (pause: 10 seconds)