题目内容
Air is very important to everything that lives. But the air we breathe is g【小题1】___ dirty. People all over the world are looking for w【小题2】___ to make it clean again.
Have you e【小题3】__ watched the smoke from chimneys rising high in the air? Have you s【小题4】__ the smoke from cars and trucks on roads or the smoke from planes? The smoke is not g【小题5】___ to breathe. If we want to keep well and strong, we need to breathe c【小题6】__ air.
W【小题7】___ more and more factories everywhere and more and more cars, trucks and planes, it is getting harder and harder to do with the air p【小题8】___.
Scientists have a【小题9】__ found ways to stop or slow down some of the things that make the air dirty. They will not stop working u【小题10】__ we have clean air again.
【小题1】.getting
【小题1】ways
【小题1】ever
【小题1】seen
【小题1】good
【小题1】.clean
【小题1】With
【小题1】pollution
【小题1】already
【小题1】until解析:
略
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