人们怀着对和平、安宁、幸福和事业成功的幢憬迎接新千年的来临。也有不少人仍然对未来世纪存有忧伤、担心、疑虑和恐惧。的确，我们将带着20世纪遗留的不少未决问题进入新世纪。科学界一是担心21世纪人口继续爆增，超过地球的承载能力。世界人曰己过60亿，比卜一千年末增长了2 With the accomplishments of peace, tranquility, happiness and cause of success, people are greeting the new millennium. Many people still have sorrows, worries, doubts and fears about the coming century. Indeed, we will enter the new century with many outstanding issues left over from the 20th century. First, the scientific community fears that population growth will continue to explode in the 21st century and exceed the carrying capacity of the Earth. The world has already passed 6 billion, an increase of 2 since the end of the millennium