In the past, people worried a lot about the {#blank#}1{#/blank#}(增长) of the world population {#blank#}2{#/blank#}(然而), there is a new {#blank#}3{#/blank#}(问题) at present. That is a too low {#blank#}4{#/blank#}(出生) rate in the past ten years. This happens in both developed and developing countries. How does this happen? There are some {#blank#}5{#/blank#}(原因): Firstly, many {#blank#}6{#/blank#}(政府) support the family planning policy to reduce the population growth, and most of them have made great progress(进步) . Secondly, more people get {#blank#}7{#/blank#}(结婚) late. They want to succeed in business and have little time to think about marriage. Thirdly, many couples like to stay in a two-person world. They don't want to have {#blank#}8{#/blank#}(宝宝) . Lastly, more women go out to have higher education or to do more important work. They would rather go to work than have children. The countries with {#blank#}9{#/blank#}(更少) births than deaths could face a serious shortage(短缺) of young workers in the future. They must think of ways to {#blank#}10{#/blank#}(解决) it.