大学英语作文:The Problem of Human Population环境污染

Directions: For this part, you are allowed 30 minutes to write a composition based on the following graph showing the growth of the world's population. The opening sentence is given and you are required to develop it into a full composition. Your part of writing should be no less than 120 words. Some useful words and phrases are provided, but you do not have to include all of them.

(Suggested words and phrases: birth control, death rate, population explosion, food shortage)
The Problem of Human Population
    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.