We often think of future. We often wonder __1__ the world will be like in a hundred years' time.
Think __2__ space. Perhaps a permanent station on the moon will have __3__(set up). Perhaps people will be able to visit the moon as __4__. 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 had plans of this kind. And there will be cities __10__ the sea.
1．______ 2.______ 3.______ 4.______ 5.______
6．______ 7.______ 8.______ 9.______ 10.______
答案：1.what 2.of 3.been set up 4.tourists/visitors/travelers 5.permitting
6.other 7.in 8.All 9.so/thus/therefore 10.under
