The world is going to have to start thinking thoroughly to save its coral reefs. Corals are comeback creatures. As the world froze and melted and sea levels rose and fell over 30,000 years, Australia's Great Barrier Reef, which is roughly the size of Italy, died and revived five times. But now, thanks to human activity, corals face the most complex mixture of conditions they have yet had to deal with.

According to the Intergovernmental Panel on Climate Change, a rise in global temperatures of 1.5°C relative to pre-industrial times could cause coral reefs to decline by 70-90%. When waters become unusually warm, corals throw out the algae, leaving reefs a ghostly white. This 'bleaching' is happening five times as often as it did in the 1970s.

Corals need protection from local sources of harm. Their ecosystems suffer from coastal currents, whether dirty water or waste from farms. Plastic and other rubbish block sunlight and spread aggressive bacteria. Governments need to carry out tighter rules on these industries, such as tougher local building codes, and to put more effort into strengthening rules against overfishing.

Many reefs that have been damaged could benefit from restoration. Coral's biodiversity offers hope, because the same coral will grow differently under different conditions. Corals of the western Pacific near Indonesia, for example, can survive higher temperatures than the same species in the eastern Pacific near Hawaii.

Stronger measures to fight against the larger threats corals face should also attract more research. Shading reefs using a polymer film as a sunscreen to cool them is under discussion for parts of the Great Barrier Reef. Other schemes to help corals involve genetic engineering, selective breeding and brightening the clouds in the sky above an area of the reef by spraying salt into the lowest ones, so that they turn away more of the sun's energy. These measures may sound extreme, but people need to get used to thinking big. Dealing with the problems caused by climate change will call for some far-reaching ideas.

【1】Thorough thinking is needed to save the coral reefs because __________.

A.corals have come back in the Great Barrier Reef in Australia

B.corals are frozen and melted five times over 30,000 years

C.corals are strong enough to survive human activity

D.human activity are threatening the condition of coral reefs

【2】The underlined word 'bleaching' most probably means _______.

A.warmingB.throwing out

C.whiteningD.dying

【3】Corals are being damaged by the following local sources EXCEPT ___________.

A.coastal water flowsB.more sunlight

C.waste from farmsD.bad bacteria

【4】Some extreme solutions to saving corals are mentioned in the passage in order to ______.

A.encourage people to come up with more ideas

B.introduce some advanced technological progress

C.raise people's awareness of protecting the environment

D.warn people of the threats and risks corals are facing

【答案】

【1】D

【2】C

【3】B

【4】A

【解析】

这是一篇说明文。文章主要讲述了由于人类活动的影响，珊瑚礁目前正面临着前所未有的生存挑战。此外，文章还鼓励大家积极想出能从长远解决问题的方法应对气候变化带来的问题。

【1】细节理解题。根据第一段的But now, thanks to human activity, corals face the most complex mixture of conditions they have yet had to deal with. (但是现在，由于人类的活动，珊瑚面临着迄今为止最为复杂的坏境)可知由于人类活动对珊瑚带来的伤害，人们必须开始全面思考拯救珊瑚礁。D. human activity are threatening the condition of coral reefs (人类活动正在威胁着珊瑚礁的环境)符合以上说法，故选D项。

【2】词义猜测题。根据第二段的When waters become unusually warm, corals throw out the algae, leaving reefs a ghostly white. This 'bleaching' is happening five times as often as it did in the 1970s.可知，当海水变得异常温暖时，珊瑚会抛出藻类，使珊瑚礁呈现出幽灵般的白色。这种bleaching现象发生的频率是20世纪70年代的5倍。结合句意，尤其是leaving reefs a ghostly white可推测划线部分的意思是“变白”。C. whitening (变白)符合以上说法，故选C项。

【3】细节理解题。根据第三段的 Their ecosystems suffer from coastal currents, whether dirty water or waste from farms. Plastic and other rubbish block sunlight and spread aggressive bacteria.(它们的生态系统受到沿海洋流的影响，无论是污水还是来自农场的废弃物。塑料和其它垃圾阻挡了阳光并传播有攻击性的细菌)可知，沿海洋流、污水、农场废弃物、有攻击性的细菌都对珊瑚有影响。B. more sunlight (更多的阳光)不符合以上说法，故选B项。

【4】推理判断题。根据最后一段的These measures may sound extreme, but people need to get used to thinking big. Dealing with the problems caused by climate change will call for some far-reaching ideas. (这些措施听起来可能有些极端，但人们需要习惯于从长远考虑。应对气候变化带来的问题需要一些深远的想法。)可推测，列举极端解决办法的目的是呼吁人们想出更多能从长远考虑的想法。A. encourage people to come up with more ideas (鼓励人们想出更多的主意)符合以上推测，故选A项。