The population problem may be the ___6___ one of the world today. People say that by the year 2010, the world's population may pass seven billion. This means we must ___7___ more food, and have smaller families with fewer ___8___ healthier children. If we don't do these, the result（结果）will be very ___9___. There will be standing room only on the earth. There won't be enough ___10___ for anybody else.

　　The United States covers a large part of the North ___1___ continent（洲）, when this land first became a nation. After ___2___ its freedom（自由）from England, it has 13 states. Each of the states had a star on the American flag. As the nation ___3___, new states were formed and there ___4___ new stars on the flag. ___5___ a long time, there were forty-eight states. In 1959 two ___6___ stars were added（加）to the flag, standing for（代表）the new states of Alaska and Hawaii.

　　___7___ were the first people of the land and great number of people came from England. It is ___8___ that reason that the language of the U. S. is English and ___9___ its culture and customs（文化习惯）are more ___10___ those of England than any other country in the world.

通读下面短文，掌握其大意，然后从1～10各小题四个选项中选出最佳答案。

　　Ten thousand years ago, the world's population was very small. For several thousand years, it grew quite 　1　. But during the last three or four hundred years it 　2　very quickly. Today it is still growing faster than 　3　. About 174 babies are born in the world 　4　just one minute. That means people have to find food for 　5　mouths more in one day.

　　The population problem may be the 　6　one of the world today. People say that by the year 2010, the world's population may be seven billion. This means we must 　7　more food, and have smaller families with fewer 　8　healthier children. If we don't do these, the results will be very 　9　. There will be standing room only on the earth. There won't be enough 　10　for anybody else.

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