[請益] TPO Mass Extinctions 疑問

看板TOEFL_iBT (TOEFL_iBT托福)作者FenderST54 (Fender)時間15年前 (2011/06/23 11:21)推噓2(2推 0噓 11→)

留言13則, 4人參與討論串1/1

這篇錯誤數突然暴增而且錯的自己竟然還看不出為什麼錯@_@ 還請解惑感謝 Paragraph 3: What could cause such high rates of extinction? There are several hypotheses, including warming or cooling of Earth, changes in seasonal fluctuations or ocean currents, and changing positions of the continents. Biological hypotheses include ecological changes brought about by the evolution of cooperation between insects and flowering plants or of bottom-feeding predators in the oceans. Some of the proposed mechanisms required a very brief period during which all extinctions suddenly took place; other mechanisms would be more likely to have taken place more gradually, over an extended period, or at different times on different continents. Some hypotheses fad to account for simultaneous extinctions on land and in the seas. Each mass extinction may have had a different cause. Evidence points to hunting by humans and habitat destruction as the likely causes for the current mass extinction. 5. Paragraph 3 supports which of the following ideas about mass extinctions? ○Scientists know the exact causes of most mass extinctions. ○Mass extinctions are unlikely to happen again in the future. ○Insects, flowering plants, and bottom-feeding predators in the oceans tend to be the first organisms to disappear during episodes of mass extinctions. ○Some mass extinctions occurred on land and in the seas at the same time. 答案為A, 但不了解為何科學家知道確切的發生原因(文章都說是hypotheses了) paragraph 4: American paleontologists David Raup and John Sepkoski, who have studied extinction rates in a number of fossil groups, suggest that episodes of increased extinction have recurred periodically, approximately every 26 million years since the mid-Cretaceous period. The late Cretaceous extinction of the dinosaurs and am monoids was just one of the more drastic in a whole series of such recurrent extinction episodes. The possibility that mass extinctions may recur periodically has given rise to such hypotheses as that of a companion star with a long-period orbit deflecting other bodies from their normal orbits, making some of them fall to Earth as meteors and causing widespread devastation upon impact. 7. According to paragraph 4, what aspect of extinction episodes does the companion-star hypothesis supposedly clarify? ○Their location ○Their frequency ○Their duration ○Their severity 答案為B, 不過我覺得應該是C, 因為句末有提到後果程度 Paragraph 7: An asteroid of this size would be expected to leave an immense crater, even if the asteroid itself was disintegrated by the impact. The intense heat of the impact would produce heat-shocked quartz in many types of rock. Also, large blocks thrown aside by the impact would form secondary craters surrounding the main crater. To date, several such secondary craters have been found along Mexico's Yucatan Peninsula, and heat-shocked quartz has been found both in Mexico and in Haiti. A location called Chicxulub, along the Yucatan coast, has been suggested as the primary impact site. 12. What is the purpose of paragraph 7 in the passage? ○It proposes a decisive new test of the Alvarez hypothesis. ○It presents additional supporting evidence for the Alvarez hypothesis. ○It explains why evidence relating to the Alvarez hypothesis is hard to find. ○It shows how recent evidence has raised doubts about the Alvarez hypothesis 答案為C, 不過B感覺也正確, 因為文章後有提到找到了隕石坑和受熱岩石的證據最後一提了 Orz 感謝耐心看到最後 14提複選題的B選項我覺得有誤 ○Researchers have observed 26-million-year cycles in extinction rates of a number of fossil groups that could all be attributed to the same cause. 為何這是正解呢? 文章有提到是 "be attributed to the samw cause."嗎? 謝謝!! -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 61.228.42.29