In the very distant geological past, all animals were aquatic. The very first vertebrates or animals with backbones, of which we have any fossil record, lived in water. These vertebrates, the fish, were adapted to underwater living. Their streamlined bodies were covered with scales to reduce surface friction: they had muscular tails so that they could swim swiftly in such a dense medium as water; and they were endowed with gills for breathing underwater. Descendants of fish-type ancestors crossed the seashore barrier and accommodated themselves to life on land. As amphibians, they possessed limbs instead of fins and lungs instead of gills. But they never became completely free of the bonds that tied them to the water; even today many amphibians return to the water to lay their eggs. Millions of years after the first clumsy amphibians crawled over the land, newer types of land dwellers appeared, these animals give rise to the present-day reptiles and mammals. They were completely converted for land dwelling, with bodies and biological activities far different from those of fish. With these special adaptations, mammals have been able to colonize the woods and meadows, the deserts and high mountains, often far removed from the sea.

The word “descendants” is closest in meaning to _____.

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ZUNIA12

• Which of the following concepts is defined in the passage?

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• The word "their" in line 12 refers to .......

• In the second paragraph, the word "stored" is closest in meaning to ............

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• The word "contacts" in paragraph 3 is closest in meaning to ..............

•  The word “exert” in bold in paragraph 1 is closest in meaning to ................

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• How many Americans are involved in telecommuting?

• Many British people wear freely when they ..................

• The four boys of the Beatles .................

• The word -lethal‖ in the second paragraph probably means ............

• What will the speaker probably discuss next?

• According to some scientists, what will the decreasing size of rain forests affect on the earth?

• Why does the author refer to Gilbert White’s book in line 2?

• If you visit an American friend at home in the evening, you may find that your friend wears .............