【学术阅读】#27
Question 1 of 5

The word “considerably” in the first paragraph is closest in meaning to

A.

actively

B.

significantly

C.

predictably

D.

consistently

正确答案:B

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译文

Sleep Patterns

Sleep patterns vary [#highlight1]considerably[/highlight1] among different animal species. Some animals, like dolphins, have unique sleep methods. Dolphins practice unihemispheric slow-wave sleep, meaning one half of their brain sleeps while the other remains awake. This adaptation allows them to surface for air and stay alert for predators even while resting.



Birds also display interesting sleep behaviors. Many bird species can sleep while flying. (A) During long migratory flights, some birds may engage in unihemispheric sleep, similar to dolphins, enabling them to navigate and avoid threats. (B) Additionally, certain birds can sleep with both hemispheres of their brain but in short bursts, allowing them to maintain continuous flight for extended periods.



(C) Sleep patterns have evolved based on environmental needs. For example, grazing animals like cows and horses sleep minimally, often standing up, which helps them stay vigilant against predators. (D) In contrast, predators such as lions and tigers can afford longer, deeper sleep because they face fewer threats. Understanding these varied sleep patterns provides insight into how animals have adapted to their habitats and survival challenges. The balance between rest and vigilance is crucial for survival, revealing the intricate adaptations across the animal kingdom.