阅读理解。

     Three key facts about rising sea levels need to be pointed out to the world's politicians and planners:

sea-level rise is now unavoidable (不可避免的), it will happen faster than most of us thought, and it will

go on for a very long time.

     Even if greenhouse gas emissions (排放) stopped tomorrow, the oceans would continue to become

larger as they get warm. The climate scientists estimate that sea-level rise may be in the range of 1 to 2

meters by 2100, with a small risk of an even greater rise.

     For many islands and low-lying regions, even small rises will cause disasters. But for most countries,

the problem is what has been built on that land: New York, Sydney and Tokyo, to mention just a few

cities. Unless something can be done, great areas of urban network will disappear under the waves. It

will take a great engineering effort to protect these cities-an effort that may be beyond economies that

have been brought to their knees.

     None of this means we should fear, and stop trying to forbid emissions. But together with these efforts,

we need to start acting now and we must stop building in danger zones.

     Billions of dollars are being spent on constructing homes, offices and roads in vulnerable (脆弱的)

coastal areas. For instance, the skyscrapers of Shanghai are being built on land that is mere 4 meters

above sea level on average, and they are sinking under the weight of the buildings. Therefore, planning

for new coastal developments is to go against reality. If we want to build a lasting heritage for our children,

we should do so on the plentiful land that is in no danger from the sea. It is one of the effective ways to

slow down climate change, and we should be acting on it now.

1. The most possible reason for the rising of sea levels should be _____.

A. greenhouse gas emission

B. temperature change of the oceans

C. vulnerable coastal area

D. fast urban development and expansion

2. New York, Sydney, and Tokyo are mentioned in this passage to show _____.

A. climate change has been completely out of control

B. modem cities are usually built along the coastline

C. the coastline is very important for modem countries

D. climate change can do harm to economies

3. The effort to protect coastal cities may be beyond economies because _____.

A. much money has been wasted to build coastal cities

B. people have lost confidence in their economies

C. economy development has made climate change worse

D. protecting the cities may cost more than what has been obtained

4. According to the author, we should _____ to deal with sea-level rise.

A. move big cities like New York and Shanghai to higher places

B. stop building skyscrapers in big cities like Sydney and Tokyo

C. build cities on the land free from the danger of sea-level rise

D. be aware of the danger of greenhouse gas emissions into the ocean