[請益] TPO20 Reading - Fossil Preservation

看板TOEFL_iBT作者 (被經濟追著跑)時間13年前 (2011/08/01 15:41), 編輯推噓0(005)
留言5則, 2人參與, 最新討論串1/2 (看更多)
各位戰友好 前幾天做了TPO20閱讀,對第三篇的幾個問題有一些疑問。 先貼上文章段落: ◆The term “fossil” often implies petrifaction,literally a transformation into stone.After the death of an organism, the soft tissue is ordinarily consumed by scavengers and bacteria. 【The empty shell of a snail or clam may be left behind, and if it is sufficiently durable and resistant to dissolution, it may remain basically unchanged for a long period of time.】 Indeed, unaltered shells of marine invertebrates are known from deposits over 100 million years old. In many marine creatures, however, the skeleton is composed of a mineral variety of calcium carbonate called【aragonite】. Although aragonite has the same composition as the more familiar mineral known as calcite, it has a different crystal form, is relatively unstable, and in time changes to the more stable calcite. 問題: ● Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information. A. When snails or clam shells left behind, they must be empty in order to remain durable and resist dissolution. B. Although snail and clam shells are durable and resist dissolving, over time they slowly begin to change. C. Although the soft parts of snails or clams dissolve quickly, their hard shells resist dissolution for a long time. D. Empty snails or clam shells that are strong enough not to disslove may stay in their original state for a long time. 這題我選C,但答案是D。 我覺得D有問題是因為文章應該沒有提到那些貝殼為長時間留在原地吧?! C應該最合理阿 另一題是: ● Why does the author mention "aragonite" in the passage? A. To emphasize that some fossils remain unaltered for millions of years. B. To contrast fossils formation in organisms with hard shells. C. To explain that some marine organisms must undergo chemical changes in order to fossilize. D. To explain why fossil shells are more likely to survive than fossil skeletons. 這題我選A,但答案是C。 我的疑惑是從文章來看,我認為aragonite不是本來就存在在生物體內嗎?只不過它和骨 骼相似但組成不同。但我看不出哪裡有經歷化學變化阿? 另外,以選項來說,雖然我不確定選項A的emphasize是否正確,但因為不認同選項C的 undergo chemical changes,所以就還是選了選項A了。 在訂正的時候連續兩題對答案有疑惑,也不覺得自己的選項是錯的阿,所以決定上來請教 高手們了! 謝謝:) -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 122.124.198.241 alan0311:original state應該是指原來的狀態吧? 原來如此!! 這一題我懂了 謝謝alan大 08/01 16:01 ※ 編輯: ms6211 來自: 122.124.198.241 (08/01 16:09)

08/01 16:03, , 1F
另句子中只有提到"empty shell",不能假設它一定原本有軟
08/01 16:03, 1F

08/01 16:04, , 2F
的部分。
08/01 16:04, 2F

08/01 16:06, , 3F
aragonite是本來就存在的沒錯,不過它主要想表達的是
08/01 16:06, 3F

08/01 16:06, , 4F
aragonite會轉換成穩定的calcite存在上億年
08/01 16:06, 4F

08/01 16:13, , 5F
我懂了,謝謝alan大的說明!!!
08/01 16:13, 5F
文章代碼(AID): #1EDbYQ4j (TOEFL_iBT)
文章代碼(AID): #1EDbYQ4j (TOEFL_iBT)