32.One such novel idea is that of inserting into the chromosomesof plants discrete genes that are not a part of the plants' naturalconstitution:specifically,the idea of inserting into nonleguminousplants the genes,if they can be identified and isolated,that fit theleguminous plants to be hosts for nitrogen-fixing bacteria. Hence,theintensified research on legumes.
這其中的一個新穎思想就是,在植物的染色體(chromosome)內(nèi)注入并非是該植物自然構造一個部分的那些不相關聯(lián)的因基:具體而言,這一思想是,在非豆科植物內(nèi)注入這樣一些基因,倘若這些基因可被辨識出來并被分離開來,而這些基因業(yè)已使豆科植物宜于充當那些具備固氮作用的細菌的寄主。由此,對豆科植物的研究日趨深入。
33.It is one of nature's great ironies that the availability ofnitrogen in the soil frequently sets an upper limit on plant growtheven though the plants' leaves are bathed in a sea of nitrogengas.
下述情形真可謂是自然界的一個莫大諷刺:土壤中所能獲得的氮肥量往往對植物的生長構成了一個上限,雖然植物的葉子被沐浴在一片氮氣的海洋中。
34.Unless they succeed,the yield gains of the Green Revolutionwill be largely lost even if the genes in legumes that equip thoseplants to enter into a symbiosis with nitrogen fixers are identifiedand isolated,and even if the transfer of those gene complexes,once theyare found,becomes possible.
除非他們能取得成功,不然的話,綠色革命的產(chǎn)量收益將在很大程度上損失殆盡,即使豆科植物中使這些植物有條件進入到與固氮細菌共生關系的基因可被辨識出來和分離開來的話,且即使這些基因綜合體(gene complex),一旦被發(fā)現(xiàn)之后,其移植得以成為可能的話。
35.Its subject(to use Maynard Mack'scategories)is "life-as-spectacle," for readers,diverted by itsvarious incidents,observe its hero Odysseus primarily from without;thetragic Iliad,however,presents "life-as-experience""readers are asked toidentify with the mind of Achilles,whose motivations render him a notparticularly likable hero.
其主題〔若借鑒梅納德。邁克(MaynardMack)的兩個分類范疇的話〕是“人生作為外部景象”,因為讀者的注意力被作品那形形色色的事件所分散,主要是從外部來觀察其主人公奧德修斯(Odyssus)的;然而,富于悲劇色彩的《伊利亞特》所表現(xiàn)的則是“人生作為內(nèi)心體驗”:讀者被要求與阿基琉斯(Achilles)的心靈產(chǎn)生共鳴,而其行為動機卻致使他變作一個并非特別惹人喜愛的主人公。
36.Most striking among the many asymmetries evident in an adultflatfish is eye placement: before maturity one eye migrates,so that inan adult flatfish both eyes are on the same side of the head.
在一條成年比目魚身上顯著存在的諸多不對稱(asymmetry)特征中,最為吸人注目的是眼睛的擺位:在成年之前,一只眼睛發(fā)生移動,因此在成年比目魚身上,兩只眼睛均位于頭部的同一側(cè)面。
37.The best evidence for the layered-mantle thesis is thewell-established fact that volcanic rocks found on oceanicislands,islands believed to result from mantle plumes arising from thelower mantle,are composed of material fundamentally different from thatof the midocean ridge system, whose source,most geologists contend,isthe upper mantle.
對于地幔分層論點來說,最好的證據(jù)乃這樣一個確認的事實,即在那些海洋島嶼——這些島嶼據(jù)信是源于由下層地幔升上來的地幔柱狀溶巖流(mantleplume)——上發(fā)現(xiàn)的火山巖石,是由與海洋中部山脊系統(tǒng)的物質(zhì)根本不同的物質(zhì)構成的,而這一海洋中部山脊系統(tǒng)的成因,大多數(shù)地質(zhì)學家論辯道,為上部地幔。
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