[ 2204阅读 ] 真题 - 5

Posted 2023-02-03 we1less

The Origin of Birds

Paragraph 1
Since the nineteenth century, the similarity between the skeletons of birds and some dinosaurs led paleontologists to speculatethat they had a common ancestor – the theropods, dinosaurs that walked on two legs. The Archaeopteryx lithographica is perhaps the most famous of all transitional forms between dinosaurs and modern birds. Archaeopteryx is really more reptile than bird. Its skeleton is almost identical to that of some theropod dinosaurs. The reptilian features include a jaw with teeth, a long bony tail, claws, separate fingers on the wing (in modern birds these bones are fused together), and a neck attached to its skull from behind (as in dinosaurs) instead of from below (as in modern birds). The birdlike traits number just two: large features and an opposable big toe, probably used for holding on to branches.It still isn’t clear whether this creature, though fully feathered, could fly. But its asymmetrical features – one side of each feather is larger than the other – suggest that it could. ○ Asymmetrical features, like airplane wings, create the “airfoil” shape necessary for aerodynamic flight. ○ We’re not sure whether Archaeopteryx is the one single species that gave rise to all modern birds. ○ But even if Archaeopteryx was not the direct ancestor of all birds, it belongs to a long string of fossils that clearly document the emergence of modern birds. ○ As these fossils get younger, we see the reptilian tail shrinking, the teeth disappearing, the claws fusing together, and the appearance of a large breastbone to anchor the flight muscles.

        asymmetrical  adj. 不对称的

1. The word “speculate” in the passage is closest in meaning to 

A realize

B believe 

C theorize 

D infer
to take to be true on the basis of insufficient evidence: THEORIZE ——“Merriam-Webster”

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2. Which of the following is presented in paragraph 1 as a reason for thinking that Archaeopteryx may have been able to fly?

A It had special adaptations for holding on to branches. 

B It was fully covered in feathers.

C Its feathers were longer on one side than on the other. 

D It had a small reptilian tail

S： 细节题  reason

D： able to fly

S：

G：C