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Unformatted text preview: arth’s history. During a geologically brief 100millionyear period, all modern animal groups (along with other animals that are now extinct) evolved. This rapid origin and diversification of animals is often referred to as “the Cambrian explosion.” 1. The word significant in the passage is closest in meaning to
sudden 2. The word relatively in the passage is closest in meaning to
characteristically 3. The word diversification in the passage is closest in meaning to
emergence of many varieties
steady decline in number
gradual increase in body size
sudden disappearance Paragraph2: Scientists have asked important questions about this explosion for more than a century. Why did it occur so late in the history of Earth? The origin of multicellular forms of life seems a relatively simple step compared to the origin of life itself. Why does the fossil record not document the series of evolutionary changes during the evolution of animals? Why did animal life evolve so quickly? Paleontologists continue to search the fossil record for answers to these questions. 4. The period discussed in the passage is referred to as an explosion because it
occurred 0.6 billion years ago, late in Earth’s history
was characterized by the unusually fast evolution of many new lifeforms.
Was characterized by widespread animal extinction
Was characterized by violent volcanic eruptions 196
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5. According to Paragraph2, which of the following is NOT a question that paleontologists asked about the Cambrian explosion?
Why was the origin of life a simple step in Earth’s history?
Why did it take so long for multicellular organisms to develop?
Why did animal life evolve so rapidly?
Why does the fossil record lack evidence of animal evolution during that time? 6. Which of the following best describes the relationship between Paragraph2 and Paragraph3?
Paragraph2 puts forward several scientific claims, one of which is rejected in Paragraph3
Paragraph2 poses several questions, and Paragraph3offers a possible answer to one of them
Paragraph2 presents outdated traditional views, while Paragraph3presents the current scientific conclusions.
Paragraph2 introduces a generalization that is illustrated by specific examples in Paragraph3 Paragraph3: One interpretation regarding the absence of fossils during this important 100millionyear period is that early animals were soft bodied and simply did not fossilize. Fossilization of softbodied animals is less likely than fossilization of hardbodied animals, but it does occur. Conditions that promote fossilization of softbodied animals include very rapid covering by sediments that create an environment that discourages decomposition. In fact, fossil beds containing softbodied animals have been known for many years. 7. The word promote in the passage is closest in meaning to
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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.
- Fall '13