1．科学的进步和生活条件的改善导致了世界人口的迅速增加。
2．但是人口过分增长会对人类社会的存在构成威胁。
3．为了保证人类社会的稳定发展。
Progress in science and the improvement of living conditions have led m the rapid growth of the world population. Modern medical science, for example, has made it possible
科学的进步和生活条件的改善导致了世界人口的迅速增长。譬如，现代医学可以使幼儿健康成长，使人们长寿。由于生活条件的改善，特别是农村生活条件的改善，家庭人门日渐增多。结果，世界人口增长如此迅猛以致于现在人口超过了50亿。
for babies to grow up healthily and for people to live longer.With improved living conditions, particularly in the countryside, people tend to have larger families. As a result, the world population has increased so rapidly that it has now exceeded 5 billion.
But the overgrowth of population presents a threat to the existence of human society. A large population demands a great deal of food supply and shelter space. However,the limited productivity and scarce natural resources can hardly meet the needs of the ever-Increasing population. Thus in the long run, the overgrowth of the world population will only harm mankind.
但是，人口过分增长对人类社会的存在构成了威胁。大量的人口需要大批的粮食供给和大量的住宅。然而，有限的生产能力和不足的`自然资源几乎不能满足日益增长的人口的需要。因此，从长远的观点看，过多的世界人口将会危害人类。控制人口
To guarantee the steady development of human society, mankind must realize the consequences resulting from a fast population growth and the importance of carrying out a family planning programme. Only by adopting effectual measures can human society develop steadily and have a bright future.
为了保证人类社会的稳定发展，人类必须意识到人口迅速增长所造成的后果和执行计划生育方针的重要性。只有采取有效措施，人类社会才能稳步发展，才会有光明的未来。