Many people in the world live in big cities ,which are often dirty and difficult places to live in .And some cities will get bigger .They will also get higher and lower ,because people will begin to live in tall buildings as well as under the ground .Scientists also say that men can begin to live in cities under the sea when there is not enough space on the land .Of course ,these new cities will be very expensive and difficult to build ,but they are not impossible .Already ,some countries are building places to live under the ground ,so their people can go there is a new war .There are underground cities in Switzerland and China ,built by the government to help some of the people live during a great war.
But will people change if they live under the ground for a long time For example ,some fish go blind if they live in the dark sea for a long time .Peop;e will not go blind because there will be light underground ,but they may change in some way .Scientists say that people who live in cities today are losing their senses of smell ,touch and taste .They can’t smell the dirty air ,and they can’t taste the chemicals in their food .These senses are not as strong as before when people lived in the country and grew their own food .The city has changed people .How will the underground city change everyone
（）1.People will be under the ground because they’ll be afraid of the war
（）2.The passage tells us people will spend much money building new cities underground
（）3.Some countries try to build some places under the ground so that people will be able to live there when summer comes
（）4.There will be enough light under the ground ,so people who will live there won’t go blind
（）5.People will lose some senses under the ground because the world is polluted