假定英语课上老师要求同桌之间互相修改作文，请你修改你同桌写的以下作文。文中共有10处语言错误，每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。
增加：在缺词处加一个漏字符号（^），并在其下面写出该加的词。
删除：把多余的词用斜线（\）划掉。
修改：在错的词下面划一横线，并在该词下面写出修改后的词。
注意：
1．每处错误及其修改均仅限1词；
2．只允许修改10处，多者（从第11处起）不计分。
The water we drink and use was running short. We all have to learn what
to stop wasting water. One of the steps that we should take are to find ways of
reusing it. Today in the most large cities, fresh water is used only once and
then it runs in waste system. But that is possible to pipe the used water to a
purifying factory, there the used water can be treated with chemical materials
by the workers so that it can reused. But even if every large city purified and
reused it’s water, we still would have enough water.