音频文件：
# L* I2 o& h; d3 _
8 w' b1 T2 v/ f对话听写训练1：
- V& h1 w# D0 X( T8 \W: Dr.Smith, I need to ask you about something in Chapter 12. Well it talks about erosion and the deposit of sediment on the deep sea floor, but I’m confused, because, well, for that to happen there would have to be some kind of force down there moving the mud or sand or whatever, right. But I thought there weren’t any waves or currents that deep in the ocean.% u: y' C% V' U' m# O5 l% `5 k
M: That’s not exactly correct. It’s true that deep down on the ocean floor we won’t have the same kinds of currents we find in shallower parts. But we do find what we call turbidity currents. This wastn’t in the book but the term came up in class. Do you remember what it means?
9 |/ d! n9 U/ RW: Uhe, turbidity currents? Oh, yeah! Isn’t that when sediment like sand or mud gets stirred up and mixes with water. And then this mixer kind of flows through the water around it, right?
0 i- I. U" J2 Z: ^' w- P) @/ MM: Good!
! _7 y& s. J6 U& GW: Umh, but I thought that only happened in rivers.' m6 |5 M, |4 g: L, g
M: Well, yes. This does occur in rivers, but we see turbidity currents deep in the ocean as well.2 l2 F5 `: i) t" E
W: But how do they get started there?+ }9 N  m; s+ O8 N: S0 n4 T
M: Earthquakes mostly, when an earthquake occurs under water, it throws up  tremendous amounts of mud or sand that becomes suspended in a layer of water near the bottom of the ocean. This layer is so much denser and heavier than other ocean water that if flows right down the slopes of the ocean floor and gains more and more speed as it moves along. Then it’s just like the winds blowing across the desert picking up sand from one place and moving it along and finally dropping it somewhere else.7 ]3 t; A7 q: c2 S) O1 G  h! F
8 T) S/ ~4 k9 ]

4 i1 m. ?; \0 ~/ |对话听写训练2：
0 a+ R6 p) t  c- E6 QW: Hey Neal, now that the midterms are over a bunch of us are getting away for the weekend to go canoeing. Wanna come along?1 h3 ~2 C+ g/ a
M: Well, uhe, it’d be great to get away, but I’ve never done it before. $ h+ w8 _$ t4 v6 m
W: None of the others have either except for me. I went once last fall. But there’ll be an instructor in each canoe the first day.
7 u! t5 G3 G7 e6 U  _+ ZM: I don’t know.
( Y$ Z$ t7 X0 P# U5 {# @W: Oh, come on. This is our last chance to take a break before finals. The scenery is beautiful, and if it gets too hot we can dive in whenever we feel like it. The river’s really calm this time of the year, no rapids to deal with.
' \6 Z7 L8 R' V1 [8 R8 d! z, UM: That’s a relief. What would I have to bring?+ f5 P/ }2 A0 C) S% p
W: Let’s see. Tom’s bringing food for the Friday night cookout for everyone. And the people who run the trip have tents set up and they supply food and drinks for all day Saturday. On the way back Sunday morning we’ll stop somewhere for breakfast. So, you just have to bring a bathing suit and a sleeping bag.
( L: J& d3 p9 t% _+ o" mM: Well, I do love camping and sleeping out. Where is this place?3 j: S. v. K5 u. @+ y! Y
W: Well, it’s about an hour and a half to the place where we meet the trip leaders. We leave our car there and they drive and the canoes upriver to the place where we start canoeing.! r% v' r" F  r, M# F9 ]
M: And who’s driving us to the meeting place?
$ |$ [: ~$ P. s% b4 A; CW: Well, I was hoping we could take your car. Mine’s in the shop again.& l* N, U2 a$ {2 B1 K0 k" g3 }% t
M: Oh, I see. It“s not me you want. It’s my car." e0 U' H$ e* Q8 ^6 Y# U
W: Don’t be silly. So what would you say?4 x4 }$ ?# j+ t7 v8 T
M: Oh, why not!
# U: n3 g2 X: o: o; U& w% ~9 O% A2 U+ x, u/ b; ?$ A5 j4 ~
演讲听写训练1：0 K( ], X- d. `+ m1 V4 p
In the 18th century French economists protested the excessive regulation of business by the government. Their motto was laisser faire. Laisser faire means “ let the people do as they choose”. In the economic sense, this meant that while the government should be responsible for things like maintaining peace and protecting property rights, it should not interfere with private business. It shouldn’t create regulations that might hinder business growth, nor should it be responsible for providing subsidies to help. In other words, governments should take a hands-off approach to business.% l4 t' k* ~( e, M
For a while in the United States, laisser faire was a popular doctrine. But things quickly changed. After the Civil War, politicians rarely opposed the governments generous support of business owners. They were only too glad to support government land grants and loans to railroad owners for example. Their regulations kept tariffs high and that helped protect American industrialists against foreign competition. Ironically in the late 19th century, a lot of people believed that the laisser faire policy was responsible for the countries industrial growth. It was generally assumed that because business owners did not have a lot of external restrictions placed on them by the government, they could pursue their own interests, and this was what made them so successful. But in fact, many of these individuals would not have been able to meet their objectives if not for government support.7 ?1 D# z( O: X4 G# u. g

% ~- e% Y! z* T: r6 g8 C演讲听写训练2：/ m1 Y6 m/ W3 y5 v; Y
Let’s begin today by discussing enzymes. Enzymes are what make many of the body’s biochemical reactions possible. Actually biochemical reactions can take place without them, but at much lower rates. In fact an enzyme may cause a reaction to proceed billions of times faster than it would otherwise.0 n& ~- h" B9 `! T$ i, b( c( P
Before I go on to the biochemical specifics of how this works, let me provide a figurative example. I think it will help illustrate the power of enzymes more clearly. Now, suppose you got a bag and you put a bunch of locks in it, just small padlocks. Then you put in all the keys that go with the locks. And you closed the bag and shook it hard. No matter how long you shook, chances are very small that any key would get inserted in any of the locks. But if you took them all out of the bag and this time used your hands to insert the keys in the locks, you could combine them much quicker.6 r4 D8 z# h8 }/ T, p
Enzymes act like your hands, quickly allowing chemical reactions that would otherwise take much longer. Now, there are 2 reasons that enzymes are so effective at enabling biochemical reactions. First, enzymes greatly reduce the amount of energy required to start the reactions, and with less energy needed the reactions can proceed a lot faster than they could without the enzyme. The second reason is that only a small amount of an enzyme is needed to enable the biochemical reaction. That’s because the chemical structure of the enzyme itself does not become altered as if enables  the reaction. So a single enzyme can be used to start the same biochemical reaction over and over again.4 n1 E2 G' B0 x* o7 j( v+ M
1 |( K/ q6 j7 k! t( z

6 g5 T, B* k7 H: }演讲听写训练3：
- Z3 [, T0 \% e% M5 a/ T3 B" K2 ^$ EToday I’d like to talk about the sculptor Henry Moore, in particular the ideas his work is based on, and also how he viewed the medium of sculpture. Moore said that to appreciate sculpture a person needs to respond to form in all of it’s 3 dimensions. He believed that this is more difficult than responding to art that is done on a flat surface, a surface such as canvas that has only 2 dimensions.
3 E8 e$ D1 F+ ~8 f9 R4 LFor example, when you’re looking at a painting you don’t have to walk around it. You don’t relate to form and shape in the same way you do when looking at sculpture, Moore paid great attention to shapes in nature such as that of bones and shells and stones. He thought that if you could appreciate the shape of something simple, like a stone that you could go on to appreciate more complex forms. He noticed that many of the stones he picked up had holes in them. One distinctive feature of Moore’s sculpture is his use of holes or opening to emphasize that he is indeed working in a 3 dimensional medium. He believed that the shape of a hole itself could have as much meaning as that of a solid mass, and could even help create a sense of mass or volume.# @: _  f+ b8 t7 e. {2 W
Moore was also interested in representing the human figure, which he sculpted in such materials as bronze, stone, and wood. His sculptures of humans contained one person as in the work Reclining Figure or several people as in the sculpture Family Group.

路漫漫其听写远兮……吾将拿刀插自己……