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IBT 新托福听力真题文本全收藏制作:先验理性(狗剩)

S: Yeah.

L: But we are still asking you to bring the book back?

S: En-hen.

L: Well, let me take a look and see what the computer says. The title was "Modern

Social Problems"?

L: OK. Oh, I see, it's been recalled/ call bake / revoke. You can keep it all semester as long as no one else requests it.

sociology

n. study of the structure and development of human society

But, someone else has. It looks like one of the professors in the sociology department has

requested it. So you have to bring it back, even though you've got extended borrowing privileges.

You can check out the book again when it's returned in a couple of weeks.

S: But I really need this book right now.

L: Do you need all of it or is there a certain section or chapter you're working with?

IBT 新托福听力真题文本全收藏制作:先验理性(狗剩)

S: I guess there is one particular chapter I've been using lately for a section of my thesis. Why?

L: Well, you can photocopy up to one chapter of the book. Why don't you do that for the chapter

you're working on right now? And by the time you need the rest of the book, maybe it will have

been returned.We can even do the photocopy for you because of the circumstances.

S: No, I left it in my dorm room. These are books I need to check out today. Is it Ok if

I bring that one by in a couple of days?

L: Actually, you need to return it today. That is if you want to check out those books today. That's

our policy.

S: Oh, I didn't know that.

L: Yeah, not a lot of people realize that. In fact, every semester we get a few students who have

their borrowing privileges suspended /cancel / stop/ completely because they haven't returned books. They're

allowed to use books only in the library. They're not allowed to check anything out because of

unreturned books.

IBT 新托福听力真题文本全收藏制作:先验理性(狗剩)

S: That's not good. I guess I should hand/head back onto the dorm right now then.

L: But, before you go, what you should do is fill out a form requesting the book back in two weeks.

You don't want to waste any time getting it back.

TPO9_Listening_2_2

Listen to part of a lecture in a geology class.

Lecturer: So, continuing our discussion of desert lakes, now I want to focus on what's known as

the "Empty Quarter". The "Empty Quarter（4分之一、地区、季节）" is a huge area of sand that covers about a quarter of the Arabian Peninsula（半岛）. Today it's pretty desolate（荒凉的）, barren and extremely hot.

*barren, infertile, sterile. / fertilizer, sterilization / hygiene, hygeian

monsoon

n. strong wind system from the Indian Ocean blowing northeast in the summer and southwest in the winter; annual season marked by strong winds and heavy rains

oasis

n. place in the desert that is fertile due to the presence of underground water; place of refuge, respite from something usual or difficult

But there've been

times in the past when monsoon 季风 rains soaked the Empty Quarter and turned it from a desert into grassland that was dotted with lakes and home to various animals. There were actually two

periods of rain and lake formation: the first one began about 35000 years ago; and the second

one dates from about 10000 years ago.

Female Student: Excuse me, Professor. But I'm confused. Why would lakes form in the desert? It's

just sand, after all.

Lecturer: Good question! We know from modern day desert lakes, like Lake Eyre, South Australia,

that under the right conditions, lakes do form in the desert. But the Empty Quarter lakes

disappeared thousands of years ago.

limestone

n. (Geology) sedimentary rock which contains mainly calcium carbonate (used as a building stone and in the manufacture of lime)

They left behind their beds or basins as limestone 石灰石

formations that we can still see today. They look like low-lying, white or grey builds, long, narrow hills with flat tops, barely a meter high. A recent study（转话题） of some of the formations presents some new theories about the area's past. Keep in mind though that

this study only looked at 19 formations. And about a thousand have been documented. So

there's a lot more work to be done. According to the study, （过程描述）two factors were important for lake

formation in the Empty Quarter: first the rains that fell there were torrential（奔流的）. So it would've been impossible for all the water to soak into the ground. Second, as you know, sand dunes 沙丘 contain other types of particles, besides sand, including clay and silt泥沙）.

clay

n. type of soil used to make pottery and bricks, soil which contains high percentage of silicates of aluminum

silt淤泥

v. fill or obstruct with silt; become filled with or obstructed by silt

x

n. fine particles of sand and other earthy matter which are carried and deposited by water

Now, when the rain fell, water ran down the sides of the dunes, carrying clay and silt particles with it. And wherever these particles settled,

they formed a pan 面板, a layer that water couldn't penetrate.

pan

n. flat shallow pan for frying food; pot for cooking food; toilet; basin, bowl

Once this pan formed, further run-off

collected, and formed a lake. Now,（转换话题） the older lakes, about half the formations, the ones started

forming 35000 years ago, the limestone formation we see, they're up to a kilometer long, but

only a few meters wide, and they're scattered along the desert floor, in valleys between the

dunes.

valley

n. low area of land located between hills or mountains

So, the theory is, the lakes formed there, along the desert floor, in these long narrow

valleys. And we know, because of what we know about similar ancient desert lakes, we know that

the lakes didn't last very long, from a few months to a few years on average. As for the more

recent lakes, the ones from 10000 years ago, well, they seemed to have been smaller, and so may have dried up more quickly. Another difference, very important today for distinguishing between older lake beds and newer ones, is the location of the limestone formations. The more recent beds are high up in the dunes. Why these differences? Well, there are some ideas about that, and they have to do with the shapes of the sand dunes, when the lakes were formed.

37000 years ago, the dunes were probably nicely rounded at the top, so the water just ran right

down their sides to the desert floor. But there were thousands of years of wind between the two

rainy periods, reshaping the dunes. So, during the second rainy period, the dunes were kind of

chopped up（切开、名词的排骨） at the top, full of hollows and ridges, and these hollows would've captured the rain

right there on the top.

ridge

n. mountain range, chain of mountains; crest, thin uppermost edge; long raised strip or rib

Now, in grassland of LakeEcosystem, we'd expect to find fossils from a

variety of animals, and numerous fossils have been found at least at these particular sites. But,

where did these animals come from? Well, the theory that has been suggested is that they

migrated in from nearby habitats where they were already living. Then as the lakes dried up, they

died out.

Emigrate / immigrate / migrate /

Habitat / habitant / habitation / inhibit / inhabitation/ inhabitant

Fossil : palaeontologist / paleontologist

Antique/ ruins : archeologist

anthropology

The study makes a couple of interesting points about the fossils, which I hope will be

looked at in future studies. At older lake sites, their fossil remains from hippopotamuses, water

buffalo（水牛）, animals that spend much of their lives standing in water, and also, fossils of cattle.

However, at the sites of the more recent lakes, there’re only cattle fossils, additional evidence for geologists that these lakes

were probably smaller, shallower, because cattle only use water for drinking. So they survive on

much less. Interestingly, there are clams and snail shells; but, no fossils of fish. We're not sure

why. Maybe there is a problem with the water. Maybe it was too salty. That's certainly true of

other desert lakes.