It has been estimated that a thousand years ago there were less than 400 million people on earth. Today, however, the world's population has amounted to 5,000 million. What is worse, it keeps growing at a surprising speed. If this trend continues, the world's population will shoot up to 7,000 million by the year 2000. This is what we call population explosion.
The rapid development of science and technology is the main cause of population explosion. We can see that the population has been growing at a tremendous speed since the Industrial and Agriculture Revolution in 1650, which raised the people's standard of living, and the emergence of modern medicine in 1550, which lowered the people's death rate.
Population explosion will result in a lot of such problems as food shortage, housing shortage and unemployment. It is time that we acted quickly to carry out the policy of birth control otherwise, man's survival on the earth will be threatened.
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据估计，一千年前地球上只有不到4亿人。然而，今天，世界人口已达50亿。更糟糕的是，它以惊人的速度持续增长。如果这种趋势继续下去，到2000年，世界人口将增长到70亿。这就是我们所说的人口爆炸。
科学技术的迅速发展是人口爆炸的主要原因。我们看到，自1650工农业革命以来，人口数量以惊人的速度增长，人民的生活水平提高了，现代医学的出现在1550，人民的死亡率下降了。
人口激增会导致食物短缺、住房短缺和失业等许多问题。该是我们迅速采取实行计划生育政策的时候了，否则人类的生存将受到威胁。
