基础训练篇（16）We must have water to live. 1the water we use is clean and fresh, it will make u

基础训练篇（16）
We must have water to live.      1    the water we use is clean and fresh, it will make us ill. The animals      2     (live) in and around lakes and rivers must also have clean water. Our rivers and lakes supply most of our water. The clear, blue water found by the first American settlers has changed. Many of our water sources are now      3    . They are filled      4     dirt and waste which cannot be cleaned out. In many places, water is not safe for us to use.
Lake Erie was      5     a beautiful lake. Now it has been called “a dying lake”. Waste from nearby homes and factories has been dumped into      6    . Fish can no longer live in much of its polluted water. George Washington once called the Potomac “     7     finest river in the world”. Now its water is no longer blue. Instead, it is soupy green. Suds(肥皂泡沫), from detergents（洗涤剂；洗衣粉） used to wash clothes, often cover the water of our rivers.
Water cannot     8    (make) in a factory. Once water is polluted, it is      9     to make it clean and safe again. We must learn to take care of the water      10     we now have.1. Unless          2. living/that live/which live          3. polluted/dirty