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(气味分子) 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(推断) 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 春天来了,五颜六色的花无处不在,但是在我们欣赏鲜花的时候,我们并不能闻到它们.
与100年之前的非工业化的美国相比,现在的美国污染越来越严重,花香比原来减少了90%,但是,如果这种趋势对人类的鼻子来说是不愉快的,它对蜜蜂和蝴蝶可能是生命危险的.
许多昆虫都通过花香找到花朵.随着污染的加重,增加了这些昆虫找到花并采蜂蜜的难度.
科研人员证实花朵释放的气味分子与污染物夹杂在一起,会降低植物的花香.
在19世纪中期,花香能够传播1000-1200米,但是现在由于环境的污染,现在花香只能传播200-300米,而且污染物会混淆蜜蜂等昆虫的鼻子,使它们更难找到花朵.
研究证实,空气中的NO和NO2气体破坏能够赋予花朵特殊气味的花香分子,这就使得昆虫很难找到花朵,从而影响农作物的授粉,这会造成世界范围的危机.
但是似乎蜜蜂等昆虫正在尝试适应这个世界.
解答 34.B.细节理解题.根据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,与100年之前的非工业化的美国相比,现在的美国污染越来越严重,花香比原来减少了90%,因此可知,花香的降低与越加严重的环境污染有联系,因此答案为B.reduced flower fragrances are connected to growing levels of air pollution
35.B.推理判断题.根据该字所在的句子But if the trend is simply unpleasant for human noses,it may be life-dangerous for bees and butterflies.其上文的内容是与100年之前的非工业化的美国相比,现在的美国污染越来越严重,花香比原来减少了90%,也就是随着污染的加重,花香不断降低,如果这种趋势继续进行,那么我们就永远闻不到花香了,这对我们来说,闻不到花香肯定是不愉悦的,但是对于蜜蜂和蝴蝶来说,是有生命危险的,因此这里的趋势应该是B.Reduce flower fragrances.即花香减少的趋势.
36.C.细节理解题.根据Many insects find flowers by following the scent produced by those flowers.可知,很多昆虫通过花朵产生的气味找到花朵,因此花朵产生气味的原因就是吸引昆虫,因此这里的答案是C.draw attention from bees and butterflies
37.B.推理判断题.根据But the bees seem to have learned to get used to the changing world.可知,但是似乎蜜蜂等昆虫正在尝试适应这个改变的世界,因此可知该题的正确答案是B.some bees have successfully get over the challenge of reduced flowers fragrance.根据倒数第二段,环境污染能够阻止昆虫找到花朵,而且能够抑制昆虫为植物传粉,这样对农作物来说无疑是灾难性的,因此A错误;根据文章的内容,随着环境的污染,花香会降低,这不但会影响人类,也会影响昆虫等找到花朵,因此C错误;根据this could put in danger agricultural harvests worldwide.可知,环境污染引起的花香降低确实会影响全球的农业,但是未来什么样,文中并没有说明,因此D错误.故选B
点评 本文是一篇警示性文章.做题时要在理解好文意的基础上,与题目有机的结合,从文章中找到相关细节性的句子与选项细细比对,进行选择或推理判断,选出符合文章内容的正确选项.做题注意灵活,有时可采用排除法或直选法确定出最终答案.