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A severe drought (干旱)has caused water levels in Southeast Asia’s Mekong

英语试题 05-04
A severe drought (干旱)has caused water levels in Southeast Asia’s Mekong River to drop to their lowest in more than 100 years. It may have harmful effects on fish, as well as the tens of millions of people living and working along the river, experts warn.
This year, the dry conditions in the Mekong region happened due to warm Pacific Ocean currents (洋流)known as the El Nino effect. But climate change is also a driving factor, experts say, causing the monsoon (季风)season to shorten sharply. The situation was made worse by water dam operators upstream, withholding water for their own purposes.
Many rice farmers in the area have been unable to plant their main crop, raising fears of a heavily decreased harvest this fall. Less water flow could also have a bad influence on fish reproduction in the Mekong River basin. This is normally the time when fish use rising water levels  to reproduce their young, but there is little sign of this happening so far this year.
Perhaps even more alarming, experts expect that droughts and damage to the water of the Mekong will become more common, and they warn that it could eventually destroy the entire ecosystem.
Starting from the Tibetan highlands, the Mekong River flows through six Asian countries, including China, Myanmar, Thailand, Laos, Cambodia and Vietnam, before emptying into the South China Sea. The river basin is home to the largest inland fishery in the world and more than 60 million people depend on it to make a living.
Few rivers in the world rise and fall with the seasons as much as the Mekong, which can drop up to 40 feet in some places at the end of the dry season. When the monsoon rains arrive, they normally produce a flood that brings with it sediments(沉积物) as well as enormous amounts of larvae(幼虫)and tiny fish, including many endangered species, such as the Mekong giant catfish, that are swept into the Tonle Sap Lake where they can grow.
28.How many reasons are there for the drought of Mekong River this year?
A. One               B.Two             C. Three             D. Four.
29.What's the attitude of experts to water flow of Mekong River in future?
A. Positive.        B. Unconcerned.        C. Worried.     D. Negative.
30.What can we know from the passage?
A.Droughts are likely to happen more frequently in the future.
B.The water levels of the Mekong River is becoming lower and lower.
C.The Mekong River starts from the Tibetan highlands and ends in the Tonic Sap Lake.
D.The harvest offish in the River hasn't been greatly a fleeted because of the droughts.
31.In which magazine can we most probably find this passage?
A. Overseas English.        B. Scientific American.
C. National Geography.     D. Tourism.

答案28-31 CCAC  
 
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