新视野大学英语读写教程听力 第二册 unit02c_new

[by:和谐英语学习网|http://www.hxen.net|和谐英语||和谐英语学习网]
[00:00.00]喜欢hxen.net，就把hxen.net复制到QQ个人资料中！Earth — a Living Planet
[00:04.39]Earth looks like a big blue marble (玻璃球);
[00:09.65]from high above the Earth and from the moon,
[00:14.29]the planet gleams and shines.
[00:19.04]The blue water in the oceans and seas of the Earth makes a dramatic image.
[00:27.22]The white clouds above the Earth add beauty to the picture.
[00:34.06]Water is the source of this beauty and the source of life on Earth.
[00:42.12]It is the reason people can live on this planet.
[00:48.56]Water is everywhere.
[00:53.03]It is in the air that people breathe.
[00:58.18]It is in the soil, the ground that grows the food.
[01:04.44]Water is in rock deep under the ground,in natural holding areas--in storage.
[01:13.80]In a real sense, water keeps Earth alive.
[01:19.88]Nature has an unchanging amount of water.
[01:26.04]Nature has a perfect system for recycling water.
[01:32.59]Water is used again and again. It falls as rain.
[01:40.76]Then it goes to one of three places.
[01:45.91]It might sink slowly through the soil into the natural holding areas in the rock.
[01:53.98]It might disappear into the air quickly -- by becoming vapor, or gas.
[02:01.54]It might run off into streams, rivers and oceans.
[02:07.69]By itself,nature can keep the balance and provide plenty of clean water for us.
[02:16.15]Nature recycles water.
[02:20.69]However,people cause problems for this natural recycling system.
[02:28.75]Nature's recycling system
[02:33.32]can work well only if people work with the system and not against it.
[02:40.99]Some ways that people upset nature are easy to understand.
[02:47.83]For example,dirty sewage water from homes
[02:53.92]and factories must not mix with drinking water.
[02:59.46]People get sick from drinking contaminated water.
[03:05.62]Sometimes water from factories goes into streams and rivers.
[03:12.96]It enters into the groundwater.
[03:17.50]It can flow into lakes too.
[03:22.03]This kind of contamination from industry (waste water from factories)
[03:29.59]can be dangerous for people.
[03:33.66]If water contains poisons  and chemicals, it is poison.
[03:40.82]Poison makes people sick; some poisons kill people as well as birds and animals.
[03:49.68]Without knowing, people can upset nature's recycling system.
[03:56.92]Lakes and rivers add beauty to the world.
[04:03.07]People enjoy water for entertainment purposes,too.
[04:09.34]People enjoy swimming and playing in the cool water of a lake in the summer.
[04:16.79]They like to ride on boats on rivers.
[04:22.22]Many people enjoy catching fish in the rivers.
[04:28.20]They fish for food and for sport.
[04:33.06]However,in some places,the water of the lakes and rivers is no longer safe.
[04:41.23]These rivers and lakes are contaminated.
[04:46.99]The fish are dying because of the chemicals from farms and factories.
[04:54.16]People cannot swim in the polluted water.
[04:59.81]There are other ways that people disturb nature.
[05:05.89]Some of these ways are not easy to understand.
[05:12.05]For example, of what use is a wet land?
[05:18.42]No one can plant crops on it.
[05:23.17]No one can build a house on it.
[05:27.35]Therefore,engineers have removed the water from some wet-lands
[05:34.58]in order to make useful land.
[05:38.83]Many shopping centers stand on dry land today,
[05:45.10]land that was once wet and full of marshes.
[05:50.64]Yet the soft and wet ground of a marsh serves an important purpose in nature.
[05:59.60]In a marsh,the surface water can sink slowly down through the soil
[06:07.16]into the rock below.
[06:10.51]Nature's holding area fills slowly with that clean,filtered water.
[06:18.50]Housing developments and shopping centers
[06:24.05]cover much of the Earth with paved and concrete surfaces.
[06:30.02]Water cannot sink through these hard surfaces.
[06:35.89]Rainwater cannot sink into the ground because of the buildings,
[06:42.34]roads,and parking lots.
[06:46.40]So it floods parking lots and flows into basements.
[06:53.35]Engineers build huge storm pipes or sewers to carry the storm water away,