文勇的新托福黄金&ccedil

ashalfthespeciesontheplanetbecameextinctwhilethereare

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Unformatted text preview: : An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some answer choices do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points. The term “Cambrian explosion” refers to the geologically brief period during which all modern animal groups evolved. ● ● ● Answer Choices ○Little is known about the stages of evolution during the Cambrian period, in part because early animals were soft bodied and could fossilize only under particular conditions. ○While animal fossils from before the Cambrian explosion have no modern descendants, many animals that evolved during the Cambrian explosion can be assigned to modern groups. ○The Cambrian period is significant because it marks the emergence of eukaryotic life­forms – organisms that have cells with true nuclei ○The Ediacara fossil formation provides the most information about the Cambrian explosion, while the earlier, Tommotian and Burgess Shale formations give clues about Precambrian evolution. ○Zoologists are awaiting the discovery of a 600­million­year­old fossil formation in order to be able to form a theory of how animal evolution progressed. ○Although the reasons for the rapid evolution of animals during the Cambrian period are not known, one proposed explanation is an abundance of niches with a lack of competitors. 199 Mail@liuwenyong.com 在在在在在在 www.liuwenyong.com 在在在在在在在在在在在在在在在,在在在在在在在在在在 在在在在在 1. ○2 2. ○3 3. ○1 4. ○2 5. ○1 6. ○2 7. ○3 8. ○3 9. ○2 10. ○4 11. ○3 12. ○2 13. ○2 14. ○1, 2, 6 200 Mail@liuwenyong.com 在在在在在在 www.liuwenyong.com 在在在在在在在在在在在在在在在,在在在在在在在在在在 在在在在 在在在在在在 在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在——在在在在在在 在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在“在在在在在在”在 在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在 在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在在...
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This note was uploaded on 09/17/2013 for the course LANGUAGE 13DL208 taught by Professor Wang during the Fall '13 term at East China Normal University.

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