The world's population (1).......... five-billion mark in 1987 and it is increasing (2).......... about 1.7% a year. At this rate of growth, the number of people in the world will double every 41 years. This rapid increas has been called the (3).......... explosion. No one knows how many people the Earth can (4).......... . Many scientists belive that the world will soon become (5).........., that is, it will have more people than it can supprt. When too many people (6).......... in a small place, life can become very difficult and (7).......... . In some places, there are so many people mere is not enough food or houses for everyone. Many families move to the cities, hoping to find work and homes. So more homes need to be (8).......... . The city spreads over more and more farming land. As the world's population grow, there is less land left for argriculture to feed all the people. 1.A:passed B:pass C:past D:passing 2.A:to B:by C:in D:of 3.A:pollution B:polluted C:population D:populated 4.A:be supored B:supports C:supporting D:support 5.A:polluted B:overpopulated C:populated D:overpopulation 6.A:to live B:living C:live D:lived 7.A:pleasant B:pleasing C:pleased D:unpleasant 8.A:built B:build C:to build D:building (cho em loi giai va giai thich voi a)