Question

6．LONDON：What could possibly be wrong with planting trees？The benefits are obvious； they  firm the soil，soak up （摄取） extra water and take carbon dioxide （二氧化碳） our of the atmosphere．
However，it now turns out that planting trees could add to global warming．
Tree roots do a great job of keeping soil firmly on the ground and out of the wind's power．The problem is that some of those dust clouds play an important part in soaking up carbon dioxide．
Huge dust storms blow out over the oceans from dry parts of North Africa and central Asia．Tons of dust are lifted and left as a thin film over the ocean surface．The dust fuels oceanic life．
Dust from China is carried east and left in the Pacific Ocean．If a tree-planting programme there is successful and the dust supply reduced，the net result may be that less carbon dioxide gets locked away in the ocean．
Andy Ridgwell，an environmental scientist from the University of East Anglia，has spent the past few years studying dust and says his work"shows clearly that the complexity of the system and the importance of not tinkering（粗劣地修补） with it without understanding the results．For this reason the need is to focus（集中） on cutting carbon dioxide giving off rather than monkeying （瞎弄） about with the land surface．"
An American scientist，Robert Jackson，has shown that when native grassland areas are invaded（侵入） by trees，carbon is lost from the soil．"We are studying why the soil carbon disappears，but one theory is that trees do a lot more of their growing above ground compared to grasses，so less carbon goes directly into the soil from trees，"says Jackson．
In wet areas of the world，the gain from trees absorbing carbon dioxide above ground seems to be outweighed（超过） by the loss of carbon from the soil below ground．Countries that plan to combat global warming by planting trees may have to think again．
Solutions to environmental problems are often more complex than they first appear，and understanding the Earth's climate is a very great challenge．
63．People usually hold the opinion thatC．
A．huge dust storms can destroy carbon dioxide
B．huge dust storms can destroy the oceans on the earth
C．huge dust storms can't do anything beneficial for man
D．planting trees is the only way to control huge dust storms
64．Andy Ridgwell，the environmental scientist，believes thatD．
A．dust plays a more important part than trees
B．trees should't have been planted in dry places
C．carbon dioxide is harmful to everything on the earth
D．environmental problems are more complex than expected
65．Robert Jackson's experiment proves thatB．
A．grassland areas should be covered by forests
B．trees hold more carbon than grasses
C．carbon can turn grass into dust
D．less carbon can make trees grow faster
66．The underlined word"combat"in the last paragraph meansB．
A．learn about            
B．fight against          
C．live with                  
D．give up．

Answer 1

分析 本文属于说明文阅读，作者通过这篇文章主要向我们描述了环境问题，植树可以坚定土壤，吸收额外的水和二氧化碳；然而发现这会增加全球变暖，使科学家们忧心．

解答 63．C．根据短文第四五段描述，可知作者认为沙尘暴对人类一点好处都没有，故选C．
64．D．根据第六段says his work"shows clearly the complexity of the system and the importance of not tinkering（粗劣地修补） with it without understanding the results．描述，可知环境问题比预期的要复杂的多．故选D．
65．B．根据倒数第二段"We are studying why the soil carbon disappears，but one theory is that trees do a lot more of their growing above ground compared to grasses，so less carbon goes directly into the soil from trees，"描述，可知树木能比草吸收更多的碳素．故选B．
66．B．词义猜测题．根据倒数第二段：Countries that plan to combat global warming by planting trees may have to think again国家计划通过种植树木来对抗全球变暖，可能要再想想；可知意为对抗；故选B．

点评 考察学生的细节理解和推理判断能力，做细节理解题时一定要找到文章中的原句，和题干进行比较，再做出正确的选择．在做推理判断题不要以个人的主观想象代替文章的事实，要根据文章事实进行合乎逻辑的推理判断．