Many places in the world need more fresh water．Every country is trying to find 1 to turn salt water into 2 water．
Why aren't there many 3 like the Symi Factory?
In some places, 4 is not hot enough or it does not shine every day．
In some places, 5 ways of heating sea water can be used．These ways 6 more money, but they work 7 than the sun． 8 boiling sea water with high heat, a lot of fresh 9 can be made quickly．
But heating is not the only way to get fresh water from salt water．Other ways are 10 ．
One way is 11 ．The fresh part of the salt water freezes first．To get fresh water, the bits of ice are taken out．
Which way is the 12 ?The one that gives the most water for the 13 money．It may be a different way for each place．
Symi's way seems very good for small, hot places．It does not make very much water 14 ．But the factory is 15 to build and costs little．
金牌教辅培优优选卷期末冲刺100分系列答案