6.As shocking as the idea of baby birds growing up in a cigarette-filled home sounds,a new study suggests that some birds may benefit from putting the stuff from cigarette butts (煙蒂) into their nests.The nicotine remaining in smoked filters (濾嘴) may serve as a natural insecticide (殺蟲劑),driving harmful insects away from the nests and the baby birds living within.Tobacco plants produce nicotine because it defends against insects that would otherwise eat the plants.
The butts are undoubtedly smelly.But birds are actually quite fond of smelly chemicals,such as those found in aromatic (芳香的) plants.Some nest-building species regularly fill their nests with fresh aromatics,possibly because the chemicals are good for the immune system or the development of the chicks.Alternatively,the plant chemicals might act as insecticides.
In the study,researchers at the Autonomous University of Tlaxcala in Mexico set up heat traps,which attract harmful insects,in 55nests around Mexico City.Some traps were lined with the stuff in smoked cigarette filters.The others were lined with the stuff from unsmoked cigarette filters,which did not contain nicotine and other smoking by-products.Whether the nest held eggs,chicks or nothing,the unsmoked cigarette traps collected more harmful insects,suggesting that it is the chemicals that drove harmful insects away.
In a second experiment,the researchers collected 28house sparrow nests and 29house finch (朱雀) nests from Mexico City immediately after the chicks flew out for food.They found that the more smoked filter stuff filled a nest,the fewer harmful insects it had.
The missing piece of the puzzle is whether the reduced number of harmful insects in the nests actually provided any benefit to the chicks.It is also unclear if nicotine or another chemical found in cigarettes may have turned the harmful insects out of the nests.
If the results hold,then this study is an example of wildlife adaptation to urbanization-or at least evidence that birds are smart and can still follow their noses in urban environments.
63.What may be the function of nicotine in cigarette butts for birds?A
A.To provide building materials for bird nests.
B.To drive harmful insects away from bird nests.
C.To protect the plants from being eaten by insects.
D.To attract baby birds to stay in the nests.
64.What is the first experiment aimed at?D
A.Proving that heat traps attract harmful insects in Mexico City.
B.Comparing smoked cigarette filters with unsmoked ones.
C.Analyzing what is produced from smoked cigarette filters.
D.Studying what it is that drives harmful insects away.
65.What can you infer from the passage?C
A.Birds tend to use insecticide to protect the baby birds.
B.Nicotine is the only chemical that drives harmful insects away.
C.Some insects are afraid of smelly chemicals in aromatic plants.
D.Unsmoked cigarette traps attract more harmful insects.
66.Where could you possibly see the passage?A
A.In a science report
B.In an urbanization essay
C.In a tobacco advertisement
D.In an anti-smoking brochure.
分析 本文通過兩個實(shí)驗(yàn)告訴我們,散發(fā)出芳香氣味的植物中的有臭味的化學(xué)物質(zhì)可以驅(qū)趕有害昆蟲.
解答 63.A.考查細(xì)節(jié)理解.由第一段a new study suggests that some birds may benefit from putting the stuff from cigarette butts (煙蒂) into their nests.The nicotine remaining in smoked filters (濾嘴) may serve as a natural insecticide (殺蟲劑可知,遺留在已抽過的濾嘴中的尼古丁可以充當(dāng)殺蟲劑,使有害的昆蟲遠(yuǎn)離鳥兒們的巢穴.故選A.
64.D.考查推理判斷.由第二段Alternatively,the plant chemicals might act as insecticides可知,第一個實(shí)驗(yàn)最終表明化學(xué)物質(zhì)可以驅(qū)逐有害昆蟲.由此可知第一個實(shí)驗(yàn)的目的應(yīng)該是研究什么將有害昆蟲驅(qū)趕走了.故選D.
65.C.考查推理判斷.由第一二段可知,鳥兒們喜歡的有臭味的化學(xué)物質(zhì)可以將有害昆蟲趕走,可知一些昆蟲是害怕這些化學(xué)物質(zhì)的.故選C.
66.A.考查文章出處.本文通過兩個實(shí)驗(yàn)告訴我們,散發(fā)出芳香氣味的植物中的有臭味的化學(xué)物質(zhì)可以驅(qū)趕有害昆蟲,這顯然是屬于科學(xué)報道范疇的文章.故選A.
點(diǎn)評 關(guān)于科教類閱讀中的一些專業(yè)詞語或生詞,考生要學(xué)會略過某些對閱讀影響不大的詞.如果必須要弄清它的意思,則可以根據(jù)詞形進(jìn)行判斷,或者從該詞在句子中的功用以及與其他詞語之間的關(guān)系猜測生詞的意思.也可根據(jù)上下文和其他詞語的按時猜測生詞的含義.