26.    M: Did you hear the weather report says we are going to get at least   
a foot of snow tomorrow?   
W: That much! That’s incredible. I can’t wait to get outside and play in   
it.   
27.    W: Growing up we never had a TV. Even now I’m not used to watching   
it much.   
M: Well, it’s kind of like reading. Some things you find are great, But a   
lit are real waste of time. You have to pick and choose.   
28.    W: I live this hat. And look, it’s on sale.   
M: Yes, but it doesn’t do much for you. What about the green one? It’s a   
little expensive. But it really looks great on you.   
29.    M: That’s a really interesting shirt. Must be from your vacation.   
W: No. But you are close. My sister brought it back from Hawaii for me.   
30.    W: Your company isn’t moving to the west coast after all.   
M: Well, not for the time being. But I’ve been looking into other   
employment opportunities here anyway. Just in case.   

31-34   
W: ok, last night you were supposed to read an article about human bones.   
Are there any comments about it?   
M: well, to begin with, I was surprised to find out there were so much   
going on in bones. I always assumed they were pretty lifeless.   
W: Well, that’s an assumption many people make. But the fact is bones are   
made of dynamic living tissue that requires continuous maintenance and   
repair.   
M: Right. That’s one of the things I found so fascinating about the   
article the way the bones repair themselves.   
W: Ok. So can you tell us how the bones repair themselves.   
M: Sure. See, there are two groups of different types of specialized¹ cells   
in the bone that work together to do it. The first group goes to an area of   
the bone that needs repair. This group of cells produce the chemical that   
actually breaks down the bone tissue, and leaves a hole in it. After that   
the second group of specialized cells comes and produce the new tissue that   
fills in the hole that was made by the first group.   
W: Very good. This is a very complex process. In fact, the scientists who   
study human bones don’t completely understand it yet. They are still   
trying to find out how it all actually works. Specifically, because   
sometimes after the first group of cells leaves a hole in the bone tissue,   
for some reason, the second group doesn’t completely fill in the hole. And   
this can cause real problems. It can actually lead to a disease in which   
the bone becomes weak and is easily broken.   
M: ok, I get it. So if the scientists can figure out what makes the   
specialized cells work, maybe they can find a way to make sure the second   
group of cells completely fills the hole in the bone tissue every time.   
That’ll prevent the disease from every occurring.   

35-38   
M: Hi Diana, mind if I sit down?   
W: Not at all, Jerry. How have you been?   
M: Good. But I’m surprised to see you on the city bus. Your car in the   
shop?   
W: No. I’ve just been thinking a lot about the environment lately. So I   
decided² the air will be a lot cleaner if we call use public transportation   
when we could.   
M: I’m sure you are right. The diesel³ bus isn’t exactly pollution free.   
W: True. They’ll be running a lot cleaner soon. We were just talking about   
that in my environmental engineering class.   
M: What could the city do? Install pollution filters in all their buses?   
W: They could, but those filters make the engines work harder and really   
cut down on the fuel efficiency. Instead they found a way to make their   
engines more efficient.   
M: How?   
W: Well, there is a material called XXX. It’s a really good insulator⁴. And   
a think coat of it get sprayed on the certain part of the engine.   
M: An insulator?   
W: Yeah. What it does is reflect back the heat of burning fuel. So the fuel   
will burn much hotter and burn up more completely.   
M: So a lot less unburning fuel comes out to pollute the air.   
W: And the bus will need less fuel. So with the saving on fuel cost, they   
say this will all pay for itself in just six months.   
M: Sounds like people should all go out and get some this stuff to spray   
their car engines.   
W: Well, it’s not really that easy. You see, normally, the materials are   
fine powder. To melt it so you can spray a coat of it on the engine parts,   
you first have to heat it over 10,000 degrees and then, well, you get the   
idea. It’s not something you or I be able to do ourselves.