As you may know,there are over 6 billion people on earth .We passed the six billion mark on october 12th ,1999!Here we h

As you may know,there are over 6 billion people on earth .We passed the six billion mark on october 12th ,1999!Here we have a few o________ interesting facts:
According to some scientists,the world’s population will r______ 7billion in 2012,and 9 billion in 2050.
THE world’s birthrate is h_______ than the death rate.Every second Scientists think it’ll take us another 120 years to double our population .
The Vatican has the s_______ population in the world :only about 900 people in the country.
Africa's population is the fastest-growing in the world.
More than one in e_______ four people in the world are youths.Nearly 70% of youths live in developing countries.In these countries ,the number of youths will c_______ to increase for another 30 years.