3．概要写作．阅读下面短文，根据其内容写一篇60词左右的内容概要．
A new study warns that about 30% of the world's people may not have enough water by the year 2025．
A private American organization called Population Action International （PAI） did the new study．It says more than 335million people lack enough water now．The people live in 28countries．Most of the countries are in Africa or the Middle East．
PAI researcher Robert Engelman says that by the year 2025，about 3000million people are short of water．At least 18more countries are expected to have severe water problems．The demand for water keeps increasing．Yet the amount f water on the Earth stays the same．
Mr．Engelman says the population in countries that lack water is growing faster than in other parts of the world．He says population growth in these countrie will continue to increase．
The report says that lack of water in the future may result in several problems．It may increase health problems．Lack of water often means drinking water is not safe．Mr．Engelman says there are problems all over the world because of diseases，like cholera that are carried in water．
Lack of water may also result in more international conflict．Countries may have to fight for water in the future．Some countries now get 60% of their fresh water from other countries．This is true of Egypt，the Netherlands，Cambodia，Syria，Sudan，and Iraq．And the report says lack of water would affect the ability to improve their economies．This is because new industries often need large amounts of water when they are beginning．
The PAI study gives several solutions to the water problem．One way，it says，is to find ways to use water for more than one purpose．Another way is to teach people to be careful not to waste water．A third way is to use less water for agriculture．The report also says long-term solutions to the water problem must include controls on population growth．
