Question

Planet Earth would be a scary place for humans if dinosaurs still ruled the world.

Though there are still some traces of life from the Jurassic Period, the Age of Dinosaurs more than 65 million years ago.

This mass extinction is believed to be the result of an asteriod（小行星）hitting Earth. A new report by the journal Biological Reviews called " The Extinction of Dinosaurs” concludes that this impact was, indeed, the cause of the dinosaurs’ demise. But the space blast(爆炸) wasn't the only reason these creatures aren't still around today.

Dinosaurs need food to survive. Meat-eating monsters like the Tyrannosaurus Rex(霸王龙) were at the top of the food chain, and fed off plant eaters like the horned Triceratops (三角恐龙). These herbivores (食草动物) were decreasing in population after the asteroid hit Earth, which left the meat-eating species less food to survive on. “In any ecosystem where you remove links to key species, that community has problems," Richard Butler, one of the review's authors, told National Ceographic.

While the herbivore population was going down, Earth's temperatures were rising when volcanoes erupted. Hot vapors and gases began wiping out some of the dinosaur population and weakening the survivors.

These changes made the asteroid's impact especially powerful. It caused more volcanoes to erupt, heated up Earth's atmosphere, and led to a sharp drop in the level of oxygen in the oceans.

With the dinosaurs gone, mammals(哺乳动物) began to evolve into bigger and more diverse species. Many animals we see today, like birds, sharks, and even some cats and dogs, appeared after the asteroid hit Earth. But none rule Earth quite like the dinosaurs did..

1. Which of the following words can replace the underlined word’’ demise" in Paragraph 2?

A. Death. B. Evolvement.

C. Presence. D. Decrease.

2. According to what Richard Butler said, what caused dinosaurs to die out?

A. A shortage of clean water.

B.A break in the food chain.

C. A small variety of animals.

D. The constant warming climate.

3. What was the negative effect of the asteroid hitting Earth?

A. Oceans became too hot for animals.

B. There was less oxygen in the oceans.

C. Earth's climate became violent.

D. The majority of the plants gradually died out.

4. The text is mainly about .

A.the evolvement of mammals on Earth

B.the gradual process of climate change

C.the importance of the balance of ecosystem

D.the cause of the extinction of the dinosaurs

Answer 1

1.A

2.B

3.B

4.D

【解析】

试题分析：如果恐龙还是世界的霸主的话，地球对人类来说会是个令人恐惧的地方。本文从小行星撞击地球的影响，食物链的断裂和致命的气候变化三方面阐述了导致恐龙死亡的原因。。

1.小题1】猜测词义题：从第二段的内容：可知《生物学研究》的一篇名为“恐龙的灭绝”新研究断定：“小行星撞击地球的影响，其实是导致恐龙死亡的原因。A. Death. 死亡 B. Evolvement.进化 C. Presence.出现 D. Decrease.减少，可知选A。

2.小题2】细节理解题：从第三段得知：恐龙彼此依靠而存活。这些食肉的怪兽，如食物链顶端的霸王龙，以三角龙类的食草动物为生。这些食草动物在小行星时代数量递减，使得食肉动物的难以生存。因此Richard Butler认为是食物链的断裂导致恐龙灭绝。选B。

3.小题3】推理判断题：根据第五段得知这些环境因素促使小行星的影响变得尤其强大。它使更多火山喷发，地球大气温度升高，导致海洋中的氧含量急剧下降。答案是B。

4.小题4】主旨大意题。根据文章从小行星撞击地球的影响，食物链的断裂和致命的气候变化三方面阐述了导致恐龙死亡的原因。得知选D。

考点：科普类文章