Larvae of many marine invertebrate species delay their metamorphosis into juveniles when cues signaling an appropriate juvenile environment are absent, thereby increasing their likelihood of thriving as juveniles and of ultimately reaching adulthood. Nevertheless, delayed metamorphosis has potential costs for juveniles, including reduced growth and increased mortality. Nearly all evidence of such costs involves species whose larvae do not feed but rather subsist stored nutrients, indicating that insufficient energy reserves may be an underlying cause of these costs. Supporting this “ hypothesis" are laboratory studies showing that in a certain “bryozoan’, the prolonged larval swimming that results from delayed metamorphosis is associated with size reductions in the juvenile feeding organ (the lophophore) and that one factor influencing the size of juveniles of certain “ barnacle species “ is how long larvae delay metamorphosis. However, other studies show that while significantly fewer juvenile “ Capitella worms “ survived to adulthood when metamorphosis had been delayed, prolonged larval swimming had no significant effect on juvenile size, suggesting, perhaps, that in some species, factors other than insufficient energy reserves account for the negative effects of the larval stresses that result from delayed metamorphosis.
1.The passage suggests that the “bryozoan’, “ barnacle species “, and “ Capitella worms “ all share of which following characteristics?
- The larvae of these species do not feed but rather subsist on stored nutrients.
- The larvae of these species are unable to undergo metamorphosis if larval swimming is significantly prolonged.
- The larvae of these species do not have enough energy to meet their needs when metamorphosis is delayed.
- The juveniles of these species manifest the negative effects of delayed metamorphosis as a decrease in size.
- The juveniles of these species are not significantly large than their respective larvae.
2. The “hypothesis” implies that compared to marine invertebrate larvae that subsist on stored nutrients, marine invertebrate larvae that feed are less likely to
- exhibit prolonged larval swimming as a result of delayed metamorphosis.
- experience negative effects as a result of delayed metamorphosis.
- thrive as juveniles in environments inappropriate for juveniles.
- delayed metamorphosis in the absence of appropriate environmental cues.
- delayed metamorphosis for an extended period of time.
3. The passage is mainly concerned with?
- weighing the relative benefits and costs of delayed metamorphosis.
- illustrating the range of cost that can result from delayed metamorphosis.
- speculating on why the costs of delayed metamorphosis have gone unrecognized.
- discussing a possible explanation of the costs of delayed metamorphosis.
- debunking the notion that the costs of delayed metamorphosis are negligible
“bryozoan’, “ barnacle species “, and “ Capitella worms “這三個出來，先看他們在結構上的位置，他們分別屬於nevertheless後面觀點的東西，接著先看一下他們三個所在的句子找得如何，一般來說這三個單子是如此的專有名詞，而且又在論點句的後面（就是轉折之後的第三句），那我可以大打說這些全都是論據，那我們只要把論點的主幹找出來即可，但是若要保險的話，分別把三個帶回去文章中，看到他們來句話的開頭分別是Supporting this “ hypothesis" are laboratory studies showing，跟other studies show，前面的那句話寫說支持這個假設（假設即論點），然後加上studies show，這不是論據都難了，所以就找找看this “ hypothesis"講啥吧，就可以有答案了。Nearly all evidence of such costs involves species whose larvae do not feed but rather subsist stored nutrients, indicating that insufficient energy reserves may be an underlying cause of these costs，沒有餵食，靠內部儲存能量。答案選（Ａ）
看到imply馬上想到推理題，直接進入托福推理題解題程序，第一步：找出相應對象，marine invertebrate larvae that subsist on stored nutrients VS. marine invertebrate larvae that feed，自己吃自己VS.拍打餵食。這裡題目出的很好心，一般只會出現問feed的這位仁兄，好的很顯然兩者關係相反，再進一步對應原句，跟上一題同一句do not feed （文章）VS.feed（題目）再次證明兩者的相反關係，然後對應句的尾巴有underlying cause of these costs，這個cost是沒有餵食的人有的，所以換句話說，有餵食的人就不會有危險，答案選（Ｂ）對應negative effects
問文章主旨，那就是看到結構圖，主題在探討delay的事情，然後轉折過才是文章的重點，所以要看到下面壞處的部分，（Ａ）沒有橫量好跟壞，好的部分已經不重要了，注重在壞＝cost=成長慢/ 死亡率高的環節上，（Ｂ）錯在range，這可以從文法上去刪除，the range of cost，介系詞去加cost已經使得這個東西變成形容詞去修飾range了，然而我們文章結構再討論cost。（Ｃ）看到結論都有成長慢/ 死亡率高怎麼可能還會unrecognized。（Ｅ）錯在這negligible，答案（Ｄ）從第一題就可以知道答案本來就該是他了，possible explanation＝studies showing....