18-Wednesday 海水淡化 302词

题材： 海水淡化　 词数： 302　 建议阅读时间： 6分钟

阅读下面的短文，回答问题。

Symi is a small island of Greece．Very little rain falls on the island．The people there tried their best to save every drop．But there had never been enough water for their needs，and they had to buy water．The water was carried there by ship．Now the island has its own“water factory”．The factory can change salt water from the sea into fresh water．

Right in the centre of the town are some long ponds．Each pond is covered with a low plastic tent．At night sea water is pumped into the ponds．During the day the hot sun shines through the tents．The sunlight turns the sea water into vapour．The vapour rises from the ponds and salt is left behind．When the vapour reaches the tents，it turns into many small drops of water．Then they run together and turn into big ones．These big drops of water run down the sides of the tents，filling the big bottles with fresh water．The salt left behind in the ponds is washed out each night．Then more sea water is pumped in．The factory is ready for the next day's work．

Symi's way of turning salt water into fresh water does not cost much．The factory is easy to build and costs little．Sea water and sunlight cost nothing．To the poor people on the island，this new way seems wonderful．Now they don't have to spend much money on fresh water any longer．

Many places in the world are in great need of fresh water．People are trying to find ways to turn salt water into fresh water．In some places，the sun is not hot enough，or it does not shine every day．In such places，people use other ways．For example，by boiling sea water，a lot of fresh water can be made quickly．But it costs much more money．In small hot places，it is better to use Symi's way，for it gives the most fresh water for the least money.

生词

Greece　n． 希腊（欧洲东南部国家）

plastic　n． 塑料：These spoons are made of plastic．这些汤匙是塑料的。

pump　n． 泵 v． 用泵抽：We pumped the basement dry．我们把地下室的积水抽干了。/The doctor pumped the poison out of the child's stomach．医生将孩子胃中的毒液抽吸出来。

vapo(u)r　n． 蒸气：water vapour水蒸气/vapour pressure气压

1．What did the people in Symi have to do before the water factory was built？

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2．What is each pond covered with？

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3．Why aren't metal tents used instead of plastic ones？

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4．When is the salt left in the ponds washed out？

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5．Why don't the people have to spend much money on fresh water any longer？

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6．Where can people use Symi's way？

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参考译文

锡米是希腊的一座小岛。该岛的降水极少。生活在那里的人们尽量节约每一滴水。但还是无法满足他们的需要，所以他们必须买水。水通过船只运送到那里。现在，这座岛屿有了自己的“水厂”，水厂可以把海里的咸水转化成淡水。

在镇子的中央有一些长形的水池。每个水池上方都覆有低矮的塑料棚。夜里，海水被抽进水池；白天，强烈的阳光透过塑料棚。阳光把海水转化为水蒸气。池中的水蒸气上升，盐分留在池子里。当水蒸气抵达塑料棚时，就变成许多小水滴。小水滴流到一起，汇成大水滴。这些大水滴从塑料棚的两边流下，装进放置淡水的大瓶子里。留在池中的盐分每晚都被冲走。然后新的海水再被抽进来。水厂开始准备第二天的工作。

锡米把咸水转化成淡水的方法花费得不多。水厂容易建设且费用低廉，海水和阳光是免费的。对岛上的穷人来说，这种新方法似乎太好了。现在，他们不用花多少钱就可以用上淡水了。

世界上的许多地方都极度缺乏淡水。人们正在想尽办法把咸水转化为淡水。在某些地方，太阳光不够强烈，或者不是每天都有太阳。在这样的地方，人们可以使用其他方法。比如，通过烧煮海水的方法以迅速制取大量淡水。但这种方法花费巨大。在地域狭小、气候炎热的地方，使用锡米岛的办法就比较好，因为它以最小的代价制取了最多的淡水。

参考答案

Wednesday 1．To save every raindrop．　2．A low plastic tent．　3．Because sunlight can't go through metal tents．　4．Each night．　5．Because the way （of turning salt water into fresh water）does not cost much．　6．In small hot places.