2.During the first period of demographic history, societies were often in danger of extinction because___.

　　A.only one in ten persons could live past 40.

　　B.there was higher mortality than fertility in most places.

　　C.it was too dangerous to have babies due to the poor conditions.

　　D.our ancestors had little enthusiasm for more children.

　　3.Which statement is true about population increase?

　　A.There might be an increase of 2.2 billion persons from now to the year 2000.

　　B.About 50,000 babies are born every six hours at present.

　　C.Between 8000 BC and the present, the population increase is about 80,000,000 persons each year.

　　D.The population increased faster between 8000BC and 1650 than between 1650 and the present.

　　4.The author of the passage intends to___.

　　A.warn people against the population explosion in the near future.

　　B.compare the demographic growth pattern in the past with that after 1650.

　　C.find out the cause for rapid increase in population in recent years.

　　D.present us a clear and complete picture of the demographic growth.

　　5.The word “demographic” in the first paragraph means___.

　　A.statistics of human.

　　B.surroundings study.

　　C.accumulation of human.

　　D.development of human.

　　第9篇答案：ABADA