7．Spring is here，the colourful flowers are seen everywhere but it is pity that many of us are not able to smell them while enjoying the colourful flowers？
Growing levels of air pollution from the factories and cars have reduced flower fragrances（芳香） by up to 90percent in the US，compared with pre-industrial levels 100years ago．
But if the trend is simply unpleasant for human noses，it may be life-dangerous for bees and butterflies．
Many insects find flowers by following the scent produced by those flowers．
The increasing pollution makes it difficult for them to find the flowers and feed on their nectar（花蜜）．
Scientists have already found that flowers produce scent molecules（氣味分子） that mix with polluted things，which breaks down the plants'sweet smell．
With more pollution in the air，the scent molecules don't remain powerful as long and travel shorter distances on the wind．In the mid-19th century，when pollution levels were first recorded，scent molecues would have been able to travel some 1，000to 1，200meters．Today，in the polluted air of large cities，scents may only make it some 200to 300meters．
Also，pollution from polluted air may fool the bee's"nose"，making their search for flowers all the more difficult．
In a paper published recently in Scientific Reports，scientists said that the nitric oxide（NO） and nitrogen dioxide （NO2）in polluted air could change many chemicals that work together to give a flower its special smell．
This，researchers said，"could prevent honeybees from reaching their flowers and prevent the pollination（授粉） of some of the world's food crops．"Or，this could put in danger agricultural harvests worldwide．
But the bees seem to have learned to get used to the changing world．"In nature honeybees use their special eyes and flower smell to find out where a flower is for the first time，"the researchers said．
34．According to the article，researchers have recently found thatB．
A．reduced flower fragrances have resulted in the dying out of many bees and butterflies
B．reduced flower fragrances are connected to growing levels of air pollution
C．polluted things in the air prevent flowers from producing scent molecules
D．flowers today can't produce enough nectar because of air pollution
35．What do the underlined words"the trend"in Paragraph 3refer to （指的是）？B
A．Increasing air pollution
B．Reduce flower fragrances．
C．Human beings'worse sense of smell
D．A growing number of power plants and cars
36．The scent molecules a plant produces are mainly toC．
A．help flowers to produce nectar
B．prevent insects from eating the plant
C．draw attention from bees and butterflies
D．clear up polluted things in the air
37．We can infer（推斷） from the article thatB．
A．future food crops won't depend on bees to complete their pollination
B．some bees have successfully get over the challenge of reduced flowers fragrance
C．bees have great advantages in their senses compared to humans．
D．world food crop production is likely to fall greatly in the near future．
分析 春天來了，五顏六色的花無處不在，但是在我們欣賞鮮花的時候，我們并不能聞到它們．
與100年之前的非工業(yè)化的美國相比，現在的美國污染越來越嚴重，花香比原來減少了90%，但是，如果這種趨勢對人類的鼻子來說是不愉快的，它對蜜蜂和蝴蝶可能是生命危險的．
許多昆蟲都通過花香找到花朵．隨著污染的加重，增加了這些昆蟲找到花并采蜂蜜的難度．
科研人員證實花朵釋放的氣味分子與污染物夾雜在一起，會降低植物的花香．
在19世紀中期，花香能夠傳播1000-1200米，但是現在由于環(huán)境的污染，現在花香只能傳播200-300米，而且污染物會混淆蜜蜂等昆蟲的鼻子，使它們更難找到花朵．
研究證實，空氣中的NO和NO2氣體破壞能夠賦予花朵特殊氣味的花香分子，這就使得昆蟲很難找到花朵，從而影響農作物的授粉，這會造成世界范圍的危機．
但是似乎蜜蜂等昆蟲正在嘗試適應這個世界．
解答 34．B．細節(jié)理解題．根據Growing levels of air pollution from the factories and cars have reduced flower fragrances（芳香） by up to 90percent in the US，compared with pre-industrial levels 100years ago．可知，與100年之前的非工業(yè)化的美國相比，現在的美國污染越來越嚴重，花香比原來減少了90%，因此可知，花香的降低與越加嚴重的環(huán)境污染有聯系，因此答案為B．reduced flower fragrances are connected to growing levels of air pollution
35．B．推理判斷題．根據該字所在的句子But if the trend is simply unpleasant for human noses，it may be life-dangerous for bees and butterflies．其上文的內容是與100年之前的非工業(yè)化的美國相比，現在的美國污染越來越嚴重，花香比原來減少了90%，也就是隨著污染的加重，花香不斷降低，如果這種趨勢繼續(xù)進行，那么我們就永遠聞不到花香了，這對我們來說，聞不到花香肯定是不愉悅的，但是對于蜜蜂和蝴蝶來說，是有生命危險的，因此這里的趨勢應該是B．Reduce flower fragrances．即花香減少的趨勢．
36．C．細節(jié)理解題．根據Many insects find flowers by following the scent produced by those flowers．可知，很多昆蟲通過花朵產生的氣味找到花朵，因此花朵產生氣味的原因就是吸引昆蟲，因此這里的答案是C．draw attention from bees and butterflies
37．B．推理判斷題．根據But the bees seem to have learned to get used to the changing world．可知，但是似乎蜜蜂等昆蟲正在嘗試適應這個改變的世界，因此可知該題的正確答案是B．some bees have successfully get over the challenge of reduced flowers fragrance．根據倒數第二段，環(huán)境污染能夠阻止昆蟲找到花朵，而且能夠抑制昆蟲為植物傳粉，這樣對農作物來說無疑是災難性的，因此A錯誤；根據文章的內容，隨著環(huán)境的污染，花香會降低，這不但會影響人類，也會影響昆蟲等找到花朵，因此C錯誤；根據this could put in danger agricultural harvests worldwide．可知，環(huán)境污染引起的花香降低確實會影響全球的農業(yè)，但是未來什么樣，文中并沒有說明，因此D錯誤．故選B
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