2019学年度人教版选修八 Unit 5Meeting your ancestorsPeriod1Warming Up & Reading学案设计(5页word版含有解析)
2019学年度人教版选修八 Unit 5Meeting your ancestorsPeriod1Warming Up & Reading学案设计(5页word版含有解析)第2页

3. The man had no alternative but hand in all stolen goods.

(hand前加to)

4. The country's economic rise is amazing, which has been widely reported.

(which→as)

5. This stone bridge dated back to 1, 500 years ago.

(dated→dates)

6. Did early people care about our appearance as we do?

(our→their)

Ⅳ. 阅读理解

It's easy to think that the globe's vast oceans would be effective barriers to the movement of land animals. An elephant can't swim across the Pacific, after all. But it turns out that plenty of plants and animals have unintentionally floated across oceans from one continent to another. Now comes evidence that tiny, trapdoor (活板门) spiders made such a journey millions of years ago.

Moggridgea rainbowi spiders can be found on Kangaroo Island, which sits off the south coast of Australia. These spiders build a silk-lined burrow (地洞) in the ground, notes Sophie Harrison, a biologist in Australia. The burrow and trapdoor provide these spiders with shelter and protection. It also provides them an out-of-sight spot from which to wait for approaching preys (猎物).

There is evidence, though, that the ancestors of them might have traveled millions of meters to get to Australia from Africa. That isn't as unlikely as it might at first seem. Australia used to be connected to other continents, long ago, as part of a supercontinent called Gondwana. And humans have been known to transport species all over the planet. But there's a third option. The spiders might have rafted (乘筏) long distances across the sea.

To figure out which story was most likely true, Harrison and her colleagues looked at the spider's genes. They looked at the genes in seven Moggridgea rainbowi spiders from Kangaroo, and five species of Moggridgea spiders from South Africa. The Australian and African spiders split off from a common ancestor some 2 million to 16 million years ago, the genes showed.

If a large block of land washes into the sea, filled with arachnids (蛛形纲动物), the spiders may be able to hide themselves throughout the journey. Plus, they can "hold their breath" and survive on stored oxygen during periods of temporary flooding, the researchers note.

【文章大意】本文是一篇说明文。研究发现, 现在生活在澳大利亚的Moggridgea rainbowi spiders与非洲的Moggridgea spiders基因相同, 应该衍生于同一祖先。

1. What is the common belief about land animals according to the text?

A. They are sensitive to natural disasters.

B. They are unlikely to move across oceans.

C. They can't make a long ocean voyage.

D. They float across oceans accidentally.

【解析】选B。推理判断题。根据第一段"It's easy to think that the globe's vast oceans would be effective barriers to the movement of land animals. An elephant