题目内容：

About 5,000 children die each day due to preventable diseases such as cholera and dysentery (痢疾) , which spread when people use unclean water for drinking or cooking. A lack of water for personal health leads to the spread of totally preventable diseases like trachoma, which has blinded some six million people.

Water troubles also trap many low-income families in a cycle of poverty and poor education and the poorest suffer most from lack of access to water. People who spend much of their time on ill health, caring for sick children, or collecting water at distances averaging 3.75 miles a day don’t have educational and economic opportunities to better their lives.

Agriculture is called the lion's share of freshwater worldwide, using some 70 percent, and industrial uses consume another 22 percent. Water areas have no political borders and nations don't always work together to share common resources, so water can be a frequent source of international conflict as well.

Day-by-day demand keeps growing, further needing water sources, from great rivers to groundwater. “We’re going deeper into debt on our groundwater use,” Postel said, “and that has very significant impacts on global water security. The rate of groundwater consumption has doubled since 1960.”

Some of Earth's groundwater is fossil water created when Earth's climate was far different. Today such water is as limited as petrol. “But we're pumping much of them out faster than ever,” Postel explained. “Humanity's growing thirst also causes a major problem about water and our ecosystems. And that also creates a cost to us, to our sons and to our grandsons, not just to nature.”

1.What does the author mainly discuss in the passage?

A. Water shortage has been a most serious challenge.

B. So many children die of polluted water every day.

C. Diseases should be properly controlled and treated.

D. Wasting water leads to the unrest of the world.

2.Why is agriculture called the lion’s share of freshwater ?

A. Because agriculture is much stronger than industry.

B. Because more people live on the agricultural produce.

C. Because agriculture uses about two-thirds of freshwater.

D. Because nations don’t always work together to save water.

3.According to what Postel said we can know ____________.

A. groundwater is rich for us to use

B. there is no need to dig deep for groundwater

C. we are consuming our next generations’ water

D. we should use river water instead of groundwater

4.What can we infer form the passage?

A. We shouldn’t use water from rivers.

B. We should protect our ecosystems.

C. Water should be distributed equally.

D. Laws should be passed for groundwater.