The world’s population has reached 7 billion（十亿）according to the United Nations（联合国）by 2011. It comes just 12 years since the total reached 6 billion - with official estimates saying the population will top 8 billion in 2025 and 10 billion before the end of the century.
And it is most likely that the 10-billionth baby will be born in the Asia-Pacific region - where the population growth rate is higher than anywhere else in the world.
Of the 2.3 billion people, the United Nations believes will be added by 2050, more than 1 billion will live in sub-Saharan Africa. The Indian subcontinent（次大陆）will add some 630 million people.

With more people to feed, more houses & medical care to provide, experts say the world’s resources（资源）will face more strain than before.
According to the picture, the population of the world reached 6 billion in ________.
A. 1987                     B. 1999                     C. 2011
We know that more than 1 billion will live in  _______ by 2050.
A. sub-Saharan Africa
B. Indian subcontinent
C. the United States
According to the picture, _______ will have the largest population in 2050.
A. China                        B. India                        C. Nigeria
The underlined word “strain” in the last paragraph（段落）means “_________”.
A. 破坏                     B. 关闭                     C. 压力
The population of the world grows ________ according to the picture.
A. slower and slower
B. faster and faster
C. smaller and smaller