The earth is our home and we must take good care of it. That is to say we must 1 the land, air and water clean. But man 2 a lot of pollution on earth since he first made fire, washed his clothes in the river and threw rubbish on the ground. Many years ago, pollution was not so serious 3 there were not so many people. There were enough 4 air, land and water. When the land or the river was dirty in one place, man moved to 5 place. Man is 6 the whole world now. So there is 7 enough clean air, nor clean land, nor clean water now. The more people there are in one place, 8 environment they maybe have. Perhaps you are afraid 9 is endless(无休止的) for people to produce pollution. 10 , we are glad to tell you that people have come to know the danger of pollution. And you can find more and more people are working hard to protect our earth. 小题1: A．have B．take C．watch D．keep 小题2: A．produced B．has produced C．is producing D．will produce 小题3: A．so B．if C．because D．but 小题4: A．clean B．old C．dirty D．new 小题5: A．other B．the other C．another D．others 小题6: A．pollute B．polluting C．clearing D．clear 小题7: A．neither B．both C．either D．none 小题8: A．the worst B．the worse C．the bad D．worse 小题9: A．that B．this C．what D．it 小题10: A．Quickly B．Especially C．Luckily D．Anyway