We must take measures to protect the environment from ______．

       A．polluting       B．being polluted        C．polluted             D．pollute

We must take measures to protect the environment from ______．

       A．polluting       B．being polluted        C．polluted             D．pollute

We must take measures to protect the environment from ______．

A．polluting            B．being polluted           C．polluted            D．pollute

We must take measures to protect the environment from ______．

A．polluting　　 B．being polluted

C. polluted D．pollute

閱讀理解。

閱讀下面短文，從每小題所給的四個選項中，選出一個最佳答案。

　　Human beings use a little less than half the water available(可利用的) worldwide. Yet occurrences (happen) of shortages and droughts(干旱) are causing hunger and poverty (poor) in some areas, and industrial and agricultural by products are polluting water supplies. Since the world's population is expected to double in the next 50 years, many experts think we are on the edge of a widespread water crisis(危機(jī)).

　　But that doesn't have to be the outcome. Water shortages do not have to trouble the world－if we start valuing water more than we have in the past. Just as we began to appreciate petroleum more after the 1970s oil crises, today we must start looking at water from a fresh economic view. We can no longer afford to consider water a actually free resource of which we can use as much as we like in any way we want.

　　Instead, far all uses except the domestic (home) demand of the poor, governments should price water to reflect its actual value. This means charging a fee for the water itself as well as for the supply costs.

　　Governments should also protect this resource by providing water in more economically and environmentally sound ways. For example, often the cheapest way to provide irrigation water in the dry tropics is through small scale projects, such as gathering rainfall in depressions(凹地) and pumping it to nearby cropland.

　　No matter what steps governments take to provide water more efficiently, they must change their legal approaches to water use. Rather than spread control among hundreds or even thousands of local, regional, and national agencies that watch various aspects of water use, countries should set up central organization to coordinate(協(xié)調(diào)) water policy.

1．What is the real cause of the possible water crisis?

[　　]

A．Only half of the world's water can be used.

B．The world population is increasing faster and faster.

C．Half of the world's water resources have been polluted.

D．People have not placed importance on water resources.

2．According to the author, the water price should ________.

[　　]

A．be reduced

B．meet the local people's demand

C．show its real value

D．be changed according to different situation

3．The author says that in some hot and dry areas it is advisable to ________.

[　　]

A．build big lakes to store water

B．build small and cheap irrigation systems

C．construct big pumping stations

D．channel water from nearby rivers to cropland

4．In order to make full use of the water supply, measures should be taken to ________.

[　　]

A．promise full protection of the environment

B．centralize the management of water resources

C．a(chǎn)sk governments at all levels to be responsible

D．encourage local and regional of water resources