1/ A very important world problem is the growth of population on the earth. 2/ It is about 1.63% every year after the number of dead people bas been taken away. 3/ There are 240 new babies are born in a minute. 4/ There will be as many as 7,200,000,000 people on the earth by the year 2012. 5/重要的是不在于现在世界人口多么庞大,而是出生率.
