Question

 阅读短文，从方框中选择适当的词并用其正确形式填空，使短文通顺、意思完整。 

twenty，reach，great，say，over，get，on， faster  and faster,year,it, pass,about

 The population problem may be one of the 1     problems in the world today. The world’s population is growing 2      Two thousand years ago,there were only 250 million people 3      the earth. Four hundred years ago,the number was 4     500  million. But at the beginning of the 5      century,the world population was about 1,700 million. In 1970,this number was 3， 600 million. In 1990，the number was five billion. A : UN report 6      that the world population will 7      six . billion by the end of the 20th century. This is just ten . 8      after it 9      five billion. People say that by the . year 2015,10       may be eight billion.    

1.        2. 3.        4.        5.       

6.        7.        8.        9.        10.       

Answer 1

 1. greatest 2. faster and faster 3. on

4. over 5. twentieth 6. says 7. pass

8. years 9. reached 10. it