世界人口日 World Population Day

China has the largest population and India come after, but according to the prediction, India will pass China in the future and becomes the country with the largest population. Every country will do the census in the certain time, in the purpose of knowing the basic situation and making better plans for the citizens.
中國是世界上人口最多的國家，印度緊隨其後，但根據預測，印度未來將會超越中國，成爲人口最多的國家。每個國家都會在一定的時間內進行人口普查，以便了解人口的基本情況，爲公民制定更好的計劃。

Take America for example. It does the census every ten years. As it has many immigrants, so the population changes greatly in the last decade. The latest census showed that the white children became less and the Latin and Hispanic had the large birth rates, so it had been predicted that white children would become minority group in the future for America. As a result, the government has taken action to increase the local people to have children.
以美國爲例。每十年做一次人口普查。由於移民很多，所以這裏的人口在過去的十年裏發生了巨大的變化。最新的人口普查顯示，白人兒童越來越少，拉丁裔和西班牙裔人口出生率較高，因此有人預測，在未來的美國，白人兒童將成爲少數民族。因此，政府採取行動，增加當地居民的生育率。

In China, thanks to the family plan, the large birth rate has been controlled and most people's life standard have been improved. Now the census predicts that China will face the aging time, so the government has changed the policy, inspiring people to have second child. The meaning of World Population Day is to remind the public of the importance of knowing the changes of the population. 
在中國，由於計劃生育，人口出生率得到了控制，大多數人的生活水平得到了提高。現在人口普查預測中國將面臨老齡化時代，所以政府改變了政策，鼓勵人們生二胎。世界人口日的意義是提醒公衆瞭解人口變化的重要性。