A、It may easily fail the bulb. B、It may worsen the images. C、It may annoy the audience. D、It may make the machine hot. A①选项都以It

M: I want to use the overhead projector for my presentation. Could you show me how to use it?
W: OK, let me show you. Just watch what I do. I... I’ll talk you through the procedure.
M: Thanks.
W: Right, well. First of all, you put the overhead projector on the table here, about 2 meters from the wall or the screen. Er... do you have a screen?
M: Er... no. I thought I’d just use the wall.
W: Oh, er... well, a screen’s better, but I suppose this wall will be all right. It is sort of white. Anyway, let’s try it. So, the next thing you have to do is press these buttons in and lift this part up until it snaps into place.
M: I see.
W: And then turn it round so the head is facing towards the screen, I mean the wall, and now we can plug it in.
M: Right, and you switch it on?
W: Yeah. Then I press the switch here on the front...
M: Right.
W: There! And the light should come on.
M: Right, OK.
W: Yeah, there we are. So, you just place your transparency here on the glass.
M: OK, there, oh!
W: Oh, no! No, the other way up.
M: Oh yes, of course.
W: That’s right, yeah. And to raise or lower the image you move this flap up or down... There, that’s better.
M: Right, OK.
W: And finally, to focus the image you turn this wheel to make it sharp. There we are, that’s not too bad.
M: Oh, that’s great, yeah. OK, thanks.
W: Oh, one more thing: whatever you do, don’t keep switching it on and off. I’m going to switch it off now. Now, when you use it in your presentation, you should leave it switched on, with a piece of paper over the glass.
M: Right, I... er... I don’t understand why you have to leave it on.
W: Well, the reason why you have to do that is you don’t want the bulb to fail. The bulb fails easily if the machine is on and off frequently. If it does, you’ll have to replace the bulb, which will be very hot and you may not have a spare anyway. So that’s about it. Any questions?
M: No, that seems all very clear. Thank you very much.
W: You’re welcome. Oh, and I really do think you need to get a screen, by the way. The picture would be much brighter than on that wall, you know.
M: Oh, OK. Well, I’ll ask Tom if he’s got one.
W: Oh, good idea! And make sure he shows you how to put it up!
M: I will. Thanks again.
1. What does the man want the woman to do?
2. How far should the overhead projector be placed from the screen?
3. Why didn’t the woman get a screen in the first place?
4. Why did the woman ask the man not to keep switching the overhead projector on and off?
5. Where will the man probably get a screen in the end?