单选题Nearly half the world’s population ______.A still lives in the developing countriesB earns less than $1 a dayC has no access to safe drinking waterD 1ives on less than $2 a day

资料：Up to 80 per cent of the world’s middle classes will live in developing countries by 2030 thanks to surprising recent gains in poverty reduction, according to a United Nations report published on Thursday.
“Never in history have the living conditions and prospects of so many people changed so dramatically and so fast.” concludes the UN’s latest Development Report. “The world is witnessing an epochal ‘global rebalancing’.”
Underpinning the improvements in the human development index（HDI） was rapid growth in countries such as China, India and Brazil, with China and India having doubled per capita economic output in less than 20 years. But the study stressed that growth and improvements in HDI spread far beyond the four Bric countries of Brazil, Russia, India and China, and included at least 40 countries that had accompanied greater economic dynamism with effective poverty-reduction policies.
Afghanistan, Sierra Leone, Ethiopia, Rwanda and Angola were among 14 countries that have recorded gains in HDI of more than 2 per cent a year since 2000. Partly as a result, the report found that worldwide extreme income poverty has plunged from 43 per cent in 1990 to just 22 per cent in 2008, including more than 500m being lifted out of poverty in China alone. The report stated that such gains had already helped the world achieve the main poverty eradication goal of the so-called Millennium Development Goals, which called for the share of people living on less than $1.25 a day to be cut by half from 1990 to 2015.
Underpinning this poverty reduction was developing countries’ increasing share of global trade, which grew from 25 per cent to 47 per cent between 1980 and 2010. “The south as a whole is driving global economic growth and societal change for the first time in centuries,” says the report.
The report found that trade among developing countries was the biggest factor in that expansion, increasing from less than 10 per cent of total global trade to more than 30 per cent. “Trade between countries in the south will overtake that between developed nations,” the report said.

The passage mainly ______.

A.discuss why developing countries are playing major role
B.illustrate a theory for poverty reduction
C.explain reasons behind a report
D.interpret the role of trade for developing countries

Rainfall in most of the Sahara is________.

A) less than five inches per year
B) less than ten inches per year
C) less than twenty inches per year
D) zero

资料：Up to 80 per cent of the world’s middle classes will live in developing countries by 2030 thanks to surprising recent gains in poverty reduction, according to a United Nations report published on Thursday.
“Never in history have the living conditions and prospects of so many people changed so dramatically and so fast.” concludes the UN’s latest Development Report. “The world is witnessing an epochal ‘global rebalancing’.”
Underpinning the improvements in the human development index（HDI） was rapid growth in countries such as China, India and Brazil, with China and India having doubled per capita economic output in less than 20 years. But the study stressed that growth and improvements in HDI spread far beyond the four Bric countries of Brazil, Russia, India and China, and included at least 40 countries that had accompanied greater economic dynamism with effective poverty-reduction policies.
Afghanistan, Sierra Leone, Ethiopia, Rwanda and Angola were among 14 countries that have recorded gains in HDI of more than 2 per cent a year since 2000. Partly as a result, the report found that worldwide extreme income poverty has plunged from 43 per cent in 1990 to just 22 per cent in 2008, including more than 500m being lifted out of poverty in China alone. The report stated that such gains had already helped the world achieve the main poverty eradication goal of the so-called Millennium Development Goals, which called for the share of people living on less than $1.25 a day to be cut by half from 1990 to 2015.
Underpinning this poverty reduction was developing countries’ increasing share of global trade, which grew from 25 per cent to 47 per cent between 1980 and 2010. “The south as a whole is driving global economic growth and societal change for the first time in centuries,” says the report.
The report found that trade among developing countries was the biggest factor in that expansion, increasing from less than 10 per cent of total global trade to more than 30 per cent. “Trade between countries in the south will overtake that between developed nations,” the report said.

“More than 500m being lifted out of poverty in China alone” illustrates ______.

A.the economic development of China is important
B.the role of some developing countries is significant for poverty reduction
C.14 countries are developing faster than China
D.it is crucial to make a clear goal first

资料：Up to 80 per cent of the world’s middle classes will live in developing countries by 2030 thanks to surprising recent gains in poverty reduction, according to a United Nations report published on Thursday.
“Never in history have the living conditions and prospects of so many people changed so dramatically and so fast.” concludes the UN’s latest Development Report. “The world is witnessing an epochal ‘global rebalancing’.”
Underpinning the improvements in the human development index（HDI） was rapid growth in countries such as China, India and Brazil, with China and India having doubled per capita economic output in less than 20 years. But the study stressed that growth and improvements in HDI spread far beyond the four Bric countries of Brazil, Russia, India and China, and included at least 40 countries that had accompanied greater economic dynamism with effective poverty-reduction policies.
Afghanistan, Sierra Leone, Ethiopia, Rwanda and Angola were among 14 countries that have recorded gains in HDI of more than 2 per cent a year since 2000. Partly as a result, the report found that worldwide extreme income poverty has plunged from 43 per cent in 1990 to just 22 per cent in 2008, including more than 500m being lifted out of poverty in China alone. The report stated that such gains had already helped the world achieve the main poverty eradication goal of the so-called Millennium Development Goals, which called for the share of people living on less than $1.25 a day to be cut by half from 1990 to 2015.
Underpinning this poverty reduction was developing countries’ increasing share of global trade, which grew from 25 per cent to 47 per cent between 1980 and 2010. “The south as a whole is driving global economic growth and societal change for the first time in centuries,” says the report.
The report found that trade among developing countries was the biggest factor in that expansion, increasing from less than 10 per cent of total global trade to more than 30 per cent. “Trade between countries in the south will overtake that between developed nations,” the report said.

The word “underpinning” in the passage refers to ______.

A.blocking
B.undergoing
C.supporting
D.stressing