和谐英语

初中英语牛津九年级下01

2012-07-06来源:和谐英语

[10:17.32]and lower their quality of life.
[10:19.72]Pollution can also harm animals and plants.
[10:24.03]There are many different forms of pollution.
[10:27.92]The three major groups are air pollution,
[10:32.23]land pollution and water pollution.
[10:36.41]Air pollution comes from many different sources
[10:40.99]not all of them are man-made.
[10:44.88]For example, dust storms in deserts
[10:49.47]and the smoke from forest fires are natural sources of air pollution.
[10:55.87]In urban areas, dirty air is more noticeable
[11:01.47]because of the fumes  from traffic and the waste from factories
[11:07.66]Air pollution can affect humans by caus-ing sore eyes
[11:14.34]and respiratory problems,
[11:17.35]especially in children and the elderly.
[11:21.76]Land pollution is caused by the deposit of solid waste
[11:28.35](e.g., cans, bottles,plastic, etc.)
[11:34.64]that cannot be broken down quickly or at all.
[11:39.24]Land pollution can affect the lives of animals and plants
[11:45.12]and it makes the en-vironment look very bad.
[11:49.50]Recycling and reusing materials
[11:54.10]can help reduce the amount of land pollution.
[11:58.41]Other methods include landfill
[12:02.59]using the rubbish to make new land -
[12:06.48]and burning the rubbish
[12:09.28]but these two methods can pollute the water and air.
[12:15.29]Water pollution re-sults when substances that are released into lakes
[12:23.39]rivers, oceans,etc. stay in the water or build up at the bottom.
[12:30.99]This form of pollution may also begin in the air if the air is polluted
[12:37.88]and causes acid rain.
[12:41.17]When it rains,the rain will then pollute the water in lakes, rivers oceans, etc.
[12:48.59]Soil erosion is one example of natural water pollution
[12:55.18]and can cause problems if the soil blocks the flow of water
[13:01.68]and leads to flooding.
[13:03.98]Pollution from human sources includes chemicals,
[13:09.18]pesticids,waste from factories and human sewage.