GRE閱讀以艱深著稱(chēng)，很多理論講解使得考生覺(jué)得如霧里云中，下面，我?guī)Т蠹襾?lái)一起做一篇題目 Over the years, biologists have suggested two main pathways bywhich sexual selection may have shaped the evolution of male birdsong.
這是本文的主題句，告訴我們一下的信息：
1.本文探討的是一個(gè)現(xiàn)象，是關(guān)于鳥(niǎo)的歌曲的性選擇問(wèn)題。
2.本文是一個(gè)新老觀點(diǎn)對(duì)比型的文章，關(guān)鍵詞在第一段中間或者第二段開(kāi)頭
3.本文談到了進(jìn)化論，那么在文章后面很可能會(huì)否定這個(gè)說(shuō)法，并且可能會(huì)進(jìn)行批駁。
4.下文會(huì)以性?xún)?nèi)和性間選擇分別展開(kāi)進(jìn)行論述。
In the first, male competition (這個(gè)就是講性?xún)?nèi)選擇了)and intrasexualselection produce relatively short, simple songs used mainly interritorial behavior. In the second, (不看也知道，這是講性間選擇)female choice andintersexual selection produce longer, more complicated songs usedmainly in mate attraction; like such visual ornamentation as thepeacock's tail, elaborate vocal characteristics increase the male'schances of being chosen as a mate, and he thus enjoys more reproductivesuccess than his less ostentatious rivals.
(以上到這里結(jié)束，做題時(shí)需要重點(diǎn)看的就是黑體字標(biāo)示的字，通常來(lái)說(shuō)，文章里面的極端語(yǔ)言需要記住它們的位置，比如最高級(jí)，比較級(jí)，表示唯一，單獨(dú)的意思的詞，可能出直接事實(shí)題)
The two pathways are not mutually exclusive, and we can expect tofind examples that reflect their interaction. (否定詞也要記住位置，可能出改善題)Teasingthem apart has been an important challenge to evolutionarybiologists.(開(kāi)始要調(diào)戲進(jìn)化論生物學(xué)家)
Early research confirmed the role of intrasexual selection. In avariety of experiments in the field, males responded aggressively torecorded songs by exhibiting territorial behavior near the speakers.(以上是性?xún)?nèi)選擇 )The breakthrough for research into intersexual selection camein the development of a new technique for investigating female responsein the laboratory. (這里告訴我們出現(xiàn)了新的突破，這是GRE所特別喜歡的東西，很可能就是本文的重點(diǎn)下面就是要進(jìn)行說(shuō)明和舉例)
When female cowbirds raised in isolation in sound-proof chamberswere exposed to recordings of male song, they responded by exhibitingmating behavior.(對(duì)于跟在論點(diǎn)之后的論述或者例子，我們沒(méi)有必要去記住太多內(nèi)容，你只要記住這是什么觀點(diǎn)的例子，以及這個(gè)例子的關(guān)鍵詞)
By quantifying the responses, researchers were able to determinewhat particular features of the song were most important. In furtherexperiments on song sparrows, researchers found that when exposed to asingle song type repeated several times or to a repertoire of differentsong types, females responded more to the latter.(遞進(jìn)關(guān)系，處理同上) The beautyof the experimental design is that it effectively rules out confoundingvariables; acoustic isolation assures that the female can respond onlyto the song structure itself.(ONLY就是唯一的意思，那么這個(gè)地方記住的就是這種方法可以去掉所有可能混淆的因素)
If intersexual selection operates as theorized, males with morecomplicated songs should not only attract females more readily butshould also enjoy greater reproductive success. At first, however,researchers doing fieldwork with song sparrows found no correlationbetween larger repertoires and early mating, which has been shown to beone indicator of reproductive success; further, common measures of malequality used to predict reproductive success, such as weight, size,age, and territory, also failed to correlate with song complexity.(看到這里，本段開(kāi)頭的觀點(diǎn)似乎是被否定了，黑體標(biāo)示的詞都是非常明顯的否定和轉(zhuǎn)折，那么我們所可以做的就是繼續(xù)往下看，各位記住，這個(gè)地方?jīng)]有必要看太細(xì)，就是因?yàn)檫@段雖有轉(zhuǎn)折，可是依然處于文章的中間，后面還有很多可能。)
The confirmation researchers had been seeking was finally achievedin studies involving two varieties of warblers.(看到這里，上一段的觀點(diǎn)就被明顯的證實(shí)了，所以一定要記住，文章還沒(méi)有結(jié)束，出現(xiàn)的轉(zhuǎn)折部分不用細(xì)看，因?yàn)榻?jīng)常會(huì)出現(xiàn)更多的轉(zhuǎn)折，而不管怎么轉(zhuǎn)，最后一次才算數(shù)。)
Unlike (千萬(wàn)記住，這個(gè)詞出現(xiàn)肯定會(huì)考!!通?？挤疵?the song sparrow, which repeats oneof its several song types in bouts before switching to another, thewarbler(下面出題會(huì)問(wèn)它) continuously composes much longer and more variablesongs without repetition. For the first time, researchers found asignificant correlation between repertoire size and early mating, andthey discovered further that repertoire size had a more significanteffect than any other measure of male quality on the number of youngproduced. The evidence suggests that warblers use their extremelyelaborate songs primarily to attract females, clearly confirming theeffect of intersexual selection on the evolution ofbirdsong.(都是重復(fù)本段的結(jié)論，不看也罷)
請(qǐng)各位記住，讀GRE文章不在于讀懂全文，你根本沒(méi)有時(shí)間讀懂。你只是 “處理 ”文章，主要線(xiàn)索就是論點(diǎn)和論據(jù)，論據(jù)大部分不用記住，只要知道在那里就是，要做快，還需要非常清楚地對(duì)于某些理論的態(tài)度，這樣才可以不至于恐慌。下面我們看題目：
21. The passage is primarily concerned with
這種題目叫做主題題，一般做法是 “三出現(xiàn) ”，主題詞必須出現(xiàn)，細(xì)節(jié)，新內(nèi)容不能出現(xiàn)。細(xì)節(jié)，指的就是把這個(gè)詞從文章拿走，文章不會(huì)受影響，依然可以存在的東西。新內(nèi)容，指的是文章完全沒(méi)有談到的東西。
(A) showing that intrasexual selection has a greater effect on birdsong than does intersexual selection
顯然性間選擇比性?xún)?nèi)選擇重要，此選項(xiàng)錯(cuò)。
(B) contrasting the role of song complexity in several species of birds(無(wú)主題詞，錯(cuò))
(C) describing research confirming the suspected relationshipbetween intersexual selection and the complexity of birdsong (就是它啦)
(D) demonstrating the superiority of laboratory work over field studies in evolutionary biology(同B)
(E) illustrating the effectiveness of a particular approach to experimental design in evolutionary biology( 同B)
22.The author mentions the peacock's tail in line 8 most probably inorder to ( 這種題叫舉例作用題，正確答案標(biāo)志有兩個(gè)詞：illustrate 和 give an exampleof 所以別的選項(xiàng)就可以不看)
(A) cite an exception to the theory of the relationship between intrasexual selection and male competition
(B) illustrate the importance of both of the pathways that shaped the evolution of birdsong (沒(méi)有談性間選擇問(wèn)題，馬上選D，選項(xiàng)業(yè)不用看，因?yàn)橹赡苁撬?
(C) draw a distinction between competing theories of intersexual selection
(D) give an example of a feature that may have evolved through intersexual selection by female choice
(E) refute a commonly held assumption about the role of song in mate attraction
23.According to the passage, which of the following is specificallyrelated to intrasexual selection? (問(wèn)的是性?xún)?nèi)選擇，還記得那個(gè)段落談這個(gè)主題多寫(xiě)么，就是第一二段，)
(A) Female choice (這個(gè)就是性間選擇)
(B) Territorial behavior (純粹的性?xún)?nèi)選擇，就是它)
(C) Complex song types
(D) Large song repertoires
(E) Visual ornamentation
24.Which of the following, if true, would most clearly demonstrate the interaction mentioned in lines 11-13?
(這是最難的題目之一，叫邏輯題，也是07年10月之后的閱讀重點(diǎn)，這種題目不用找內(nèi)容對(duì)應(yīng)，因?yàn)樗闹攸c(diǎn)是假設(shè)某一觀點(diǎn)成立，那一個(gè)能夠最大支持或反對(duì)這個(gè)觀點(diǎn)，這些事實(shí)不是來(lái)自于文章，所以必須先看清楚11-13說(shuō)了什么?，F(xiàn)在做到題目看完全不遲，因?yàn)槟慵词箘偛趴戳?，做到這里也可能混淆，現(xiàn)在考了才回去看，非常直接，清晰。11-13行其實(shí)就是第二段的開(kāi)頭，不過(guò)請(qǐng)記住，GRE為了增加難度，真正的結(jié)論通常在上面一句或者下面一句，這種題目的難度就非常大了，因此，真正的要說(shuō)明的觀點(diǎn)是：The two pathways are not mutually exclusive, andwe can expect to find examples that reflect their interaction.)
(A) Female larks respond similarly both to short, simple songs and to longer, more complicated songs. (沒(méi)有性的吸引)
(B) Male canaries use visual ornamentation as well as elaborate song repertoires for mate attraction. (同上)
(C) Both male and female blackbirds develop elaborate visual and vocal characteristics. (同上)
(D) Male jays use songs to compete among themselves and to attract females. (性?xún)?nèi)性間都有，就是它)
(E) Male robins with elaborate visual ornamentation have as muchreproductive success as rivals with elaborate vocal characteristics.(只有性間)
25. The passage indicates that researchers raised female cowbirds inacoustic isolation in order to (這次我們運(yùn)氣不那么好了，不過(guò)還是可以做，in orderto前面的內(nèi)容是例子，觀點(diǎn)一般在例子的前面，把鳥(niǎo)兒關(guān)在隔音室里是為什么呢，當(dāng)然就是為了隔開(kāi)別的因素。選A)
(A) eliminate confounding variables
(B) approximate field conditions
(C) measure reproductive success
(D) quantify repertoire complexity
(E) prevent early mating
26. According to the passage, the song sparrow is unlike(這就是UNLIKE出的題目，這叫做強(qiáng)對(duì)比，其實(shí)只要強(qiáng)對(duì)比出現(xiàn)，肯定都會(huì)出題。類(lèi)似的語(yǔ)言標(biāo)志還有：previously,bycontrast等) the warbler in that the song sparrow (主語(yǔ)是the songsparrow，肯定選表示簡(jiǎn)單的選項(xiàng))。
(A) uses songs mainly in territorial behavior (沒(méi)關(guān)系)
(B) continuously composes long and complex songs (復(fù)雜)
(C) has a much larger song repertoire (復(fù)雜)
(D) repeats one song type before switching to another (重復(fù)，簡(jiǎn)單)
(E) responds aggressively to recorded songs(沒(méi)關(guān)系)
27.The passage suggests that the song sparrow experiments mentionedin lines 37-43 failed to confirm the role of intersexnal selectionbecause (失敗的原因就在否定詞)At first, however, researchers doing fieldwork withsong sparrows found no correlation between larger repertoires and earlymating, which has been shown to be one indicator of reproductivesuccess
原因就是沒(méi)有關(guān)系，答案肯定有否定詞。
A) females were allowed to respond only to the song structure (沒(méi)有)
(B) song sparrows are unlike other species of birds (unlike不是否定)
(C) the experiments provided no evidence that elaborate songs increased male reproductive success (就是它)
(D) the experiments included the songs of only a small number of different song sparrows (沒(méi)有)
(E) the experiments duplicated some of the limitations of previous field studies (沒(méi)有)