33.It is one of nature's great ironies that the availability of nitrogen in the soil frequently sets an upper limit on plant growth even though the plants' leaves are bathed in a sea of nitrogen gas.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(gòu)成了一個上限，雖然植物的葉子被沐浴在一片氮?dú)獾暮Ｑ笾小?BR> 34.Unless they succeed，the yield gains of the Green Revolution will be largely lost even if the genes in legumes that equip those plants to enter into a symbiosis with nitrogen fixers are identified and isolated，and even if the transfer of those gene complexes，once they are 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(jìn)入到與固氮細(xì)菌共生關(guān)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's categories）is “l(fā)ife-as-spectacle，” for readers， diverted by its various incidents，observe its hero Odysseus primarily from without；the tragic Iliad，however，presents “l(fā)ife-as-experience”：readers are asked to identify with the mind of Achilles，whose motivations render him a not particularly likable hero.
其主題〔若借鑒梅納德。邁克（Maynard Mack）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(jī)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 adult flatfish is eye placement： before maturity one eye migrates，so that in an 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 the well-established fact that volcanic rocks found on oceanic islands，islands believed to result from mantle plumes arising from the lower mantle，are composed of material fundamentally different from that of the midocean ridge system， whose source，most geologists contend，is the upper mantle.
對于地幔分層論點(diǎn)來說，的證據(jù)乃這樣一個確認(rèn)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（mantle plume）——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(gòu)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(xué)家論辯道，為上部地幔。
38.Some geologists，however，on the basis of observations concerning mantle xenoliths， argue that the mantle is not layered，but that heterogeneity is created by fluids rich in “incompatible elements” （elements tending toward liquid rather than solid state）percolating upward and transforming portions of the upper mantle irregularly，according to the vagaries of the fluids' pathways.
但是，某些地質(zhì)學(xué)家，以對地幔捕虜巖體（xenolith）所作的觀察為依據(jù)，指出地幔并非是分層排列的，相反，地幔的異質(zhì)性是由那些富含“不相容成分”的流質(zhì)構(gòu)成的，這些成分趨向于流體而非固體的狀態(tài)，自下而上滲透擴(kuò)散，并依照這些流質(zhì)流向的任意性，不規(guī)則地將上部地幔的某些部分予以改變。
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(jìn)入到與固氮細(xì)菌共生關(guān)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's categories）is “l(fā)ife-as-spectacle，” for readers， diverted by its various incidents，observe its hero Odysseus primarily from without；the tragic Iliad，however，presents “l(fā)ife-as-experience”：readers are asked to identify with the mind of Achilles，whose motivations render him a not particularly likable hero.
其主題〔若借鑒梅納德。邁克（Maynard Mack）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(jī)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 adult flatfish is eye placement： before maturity one eye migrates，so that in an 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 the well-established fact that volcanic rocks found on oceanic islands，islands believed to result from mantle plumes arising from the lower mantle，are composed of material fundamentally different from that of the midocean ridge system， whose source，most geologists contend，is the upper mantle.
對于地幔分層論點(diǎn)來說，的證據(jù)乃這樣一個確認(rèn)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（mantle plume）——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(gòu)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(xué)家論辯道，為上部地幔。
38.Some geologists，however，on the basis of observations concerning mantle xenoliths， argue that the mantle is not layered，but that heterogeneity is created by fluids rich in “incompatible elements” （elements tending toward liquid rather than solid state）percolating upward and transforming portions of the upper mantle irregularly，according to the vagaries of the fluids' pathways.
但是，某些地質(zhì)學(xué)家，以對地幔捕虜巖體（xenolith）所作的觀察為依據(jù)，指出地幔并非是分層排列的，相反，地幔的異質(zhì)性是由那些富含“不相容成分”的流質(zhì)構(gòu)成的，這些成分趨向于流體而非固體的狀態(tài)，自下而上滲透擴(kuò)散，并依照這些流質(zhì)流向的任意性，不規(guī)則地將上部地幔的某些部分予以改變。