英语完形填空The water problem may be the most serious problem in t

英语完形填空
The water problem may be the most serious problem in the world.You may think it is 1（s ） because nearly 70% of the earth's surface is covered 2（w ）water.Yes,it is true.But about 97% of it is sea water or salt water,and people can't 3（d ）it .People can only drink and use the 3（o ）3%.The water comes only from 5 （r ）,lakes and underground.And we cannot even use all of that,6（b ） the iceberg covers some of it.Even more,people have polluted some of the water.
Of course,the little water is still 7（e ） for us if people try to recycle some of it.But today more and more people 8（n ）more and more water.We must take steps to solve these 9（p ）.one of the first steps is to develop ways of reusing water.Another way is to use sea water by
10（t ） the salt out,and this has begun in many countries.But it costs too much.