语法填空练习一 With the 1.________ (develop) of industry, air pollution is getting more and more serious. In Beijing, many people suffer different kinds of illnesses because 2.______ air pollution. Air pollution is caused by the following 3._____(reason): about half of the problem is caused by vehicles. There are more and more cars, buses on the roads, and they give off 4.________ (poison) gases. 25% of air pollution is caused by factories. Another factor is the smokers. Smoking not only does harm to their health 5.______ to others. 6._______ these, about 10%of air pollution is caused by other reasons. We should take some measures to fight 7.______ pollution. New fuel can be used to take 8.______place of gas. We can plant more trees. If everybody realizes the 9.________ (important) of environment and does something to stop pollution, the problem will 10._________ (solve). 语法填空练习二 We often think of future. We often wonder 1.______ the world will be like in a hundred years’time. Think of space. Perhaps a permanent station on 2.________ moon will 3.________ (set) up. Perhaps people will be able to visit the moon as 4.________ (visit). Cheap rockets for space travel will have been developed, 5.________ (permit) long journeys through the solar system. When that time comes, people will be taking holidays in space and visiting 6.________ planets. Great progress will have been made 7.________ medicine, too. Pollution will have been controlled in a hundred years’ time. 8.________ the world will have been developed—even Antarctica. We will have used up most of the earth’s land to build our cities, 9.________ floating cities will have been built. The Japanese have already plans of this kind. And there will be cities 10.________ the sea.