8.No offence to you,but scientists have found that mosquitoes may find your feet as attractive as Limburger cheese.If that's you,don't feel embarrassed-it doesn't mean you're not washing them enough.Mosquitoes are simply attracted by certain DNA.
A UK research team recently investigated the genetic role in mosquito attraction by testing the bite appeal of 18twin sisters and 18 non-twin sisters.In a series of tests,20hungry mosquitoes were released into the end of a Y-shaped tube and allowed to choose left or right.Down either path was one sister's hand,releasing its delicious natural odors but protected from bites behind a net screen.After testing all 36pairs,scientists found that the twin pairs had consistently more similar attraction scores than the non-twin ones did-specifically,67 percent of a person's insect appeal had to do with her genes.
So what's the deal:does DNA smell?Thankfully,no.But specific DNA does attract unique species of microbacteria to your body-and those are what mosquitoes just can't resist.
Each of us,right now,is covered with about 100 trillion microbes(微生物),outnumbering our human DNA ten to one.Maybe weirder still:scientists believe we share only a fraction of these microbial species with one another,making our'microbiome'-the world of bacteria living in and on us-unique,just like our fingerprints.In addition to producing many of the vitamins and chemicals in our blood,our microbiome is thought to be responsible for most of our distinct odors as well.
Different mosquitoes prefer different smells from different parts of the body-that's why Anopheles gambiae (known for spreading malaria) prefers biting hands and feet,while others go right for the armpits or groin.And those smells come from chemicals produced by our microbiomes.So the next time a group of hungry mosquitoes swarms your cousin but leaves you bite-free,thank your DNA for the world of microscopic creatures on your skin that produce just the right smell to keep the bloodsuckers away.
32.The research conducted by the UK team suggested thatD.
A.more mosquitoes chose the twin pairs
B.more mosquitoes chose the non-twin pairs
C.Non-twin pairs had more similar attraction than twin pairs
D.most insect appeal had to do with a person's DNA
33.What does the word"those"in Paragraph 3 refer to?B
A.a(chǎn) specific DNA
B.the microbateria
C.the smell of body
D.the attractive blood
34.From Paragraph 4,we can learn thatB.
A.we are part of our microbiome.
B.our microbiome contributes to our distinct odors
C.our microbiome will decide our fingerprints in some way
D.our microbiome produces vitamins and nutrients in our blood
35.What does the passage mainly talk about?D
A.We are attractive to the mosquitoes.
B.Different mosquitoes prefer different smells.
C.DNA that attracts mosquitoes makes us unique.
D.Mosquitoes are simply attracted by certain DNA.
分析 短文主要講了科學(xué)家通過研究表明蚊子喜歡咬具有某一些DNA的人,并且不同的蚊子也喜歡咬人身體不同的部位.
解答 32.D,細(xì)節(jié)理解題,根據(jù)句子67 percent of a person's insect appeal had to do with her genes.可知,吸引大多數(shù)昆蟲的是人的DNA,故答案為D.
33.B,單詞指代題,分析整個句子,代詞those指代的是前文提到的unique species of microbacteria,故答案為"微生物",選B.
34.B,細(xì)節(jié)理解題,根據(jù)第四段句子our microbiome is thought to be responsible for most of our distinct odors as well可知,我們的微生物造成我們不同的氣味,故答案為B.
35.D,主旨大意題,短文主要講了科學(xué)家通過研究表明蚊子喜歡咬具有某一些DNA的人,并且不同的蚊子也喜歡咬人身體不同的部位,故答案為D.
點評 解答任務(wù)型閱讀理解題,首先對原文材料迅速瀏覽,掌握全文的主旨大意.因為閱讀理解題一般沒有標(biāo)題,所以,速讀全文,抓住中心主旨很有必要,在速讀的過程中,應(yīng)盡可能多地捕獲信息材料.其次,細(xì)讀題材,各個擊破.掌握全文的大意之后,細(xì)細(xì)閱讀每篇材料后的問題,弄清每題要求后,帶著問題,再回到原文中去尋找、捕獲有關(guān)信息.最后,要善于抓住每段的主題句,閱讀時,要有較強的針對性.對于捕獲到的信息,要做認(rèn)真分析,仔細(xì)推敲,理解透徹,只有這樣,針對題目要求,才能做到穩(wěn)、準(zhǔn).