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[C]The first animals with true backbones were the fishes, first known in the rocks of 375 million years ago. About 300 million years ago the amphibians, the animals able to live both on land and in water, appeared. They were giant, sometimes 8 feet long, and many of them lived in the swampy pools in which our coal seam, or layer, or formed. The amphibians gave rise to the reptiles and for nearly 150 million years these were the principal forms of life on land, in the sea, and in the air.
[D]The best index fossils tend to be marine creatures. These animals evolved rapidly and spread over large areas of the world.
[E]The earliest animals whose remains have been found were all very simple kinds and lived in the sea. Later forms are more complex, and among these are the sallies , relations of the starfishes, which had long arms and were attached by a long stalk to the sea bed, or to rocks.
仿真试题
Passage 1
1.Which of the following can reflect the ever-changing ethnic structure of America?
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