Vì sao ít người tách nước ngọt từ nước biển?
Cập nhật: 07:11 27/06/2007 GMT+7
Khi các thành phố lún sâu vì hết nước ngọt, giải pháp hiển nhiên sẽ là tách nước biển. Song thực tế, công nghệ này tiến rất chậm trong hàng nghìn năm qua.
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