Question

    Blue whales, the earth’s largest animals, call to others of their kind, though exactly what these cries communicate remains a mystery. But these sounds have begun evolving (演变). Since at least the 1960s, the pitch (音调) of Antarctic blue whales has downshifted. Scientists have theories as to why: all involving humans.

The deepening of their sounds is not unique. Many blue whales around the world have also dropped their pitch. In a study last year that analyzed more than 1 million individual recordings of whale calls, scale shifts were found across species, and among populations that don’t necessarily interact with one another. This is to say, whatever has caused the change doesn’t seem to have a specific geographic origin.

The underwater noises caused by ocean traffic and at-sea industries might seem a likely criminal. However, scientists have identified lowered pitches even across populations of whales that live in seas without major shipping routes.

One possible explanation for the change is the achievements of global conservation efforts. As their populations have grown, then, the whales may have decreased their volume because they are more likely to be communicating over short distances.

Last year’s study of whale calls also suggests a threatening reason for the drop in pitch, however. Perhaps whales don't need to be so loud because sound waves travel farther in oceans made acidic by the absorption of carbon dioxide.

Carbon dioxide in the atmosphere, meanwhile, may also indirectly influence whale voices in other ways. Recent study shows that, during the summer, the whales must use their top volume to be heard in the cracking ice — a natural sound increased by unnatural processes, as rising temperatures worsen ice-melt. So the impacts of a warming planet may modulate animal sounds even in remote places.

1.To what extent is whales’ pitch drop?

A.Across the species.

B.In the Antarctic Ocean.

C.Among some populations.

D.Within one million individuals.

2.What causes the evolving of whales’ pitch according to the text?

A.Less communication and more threat.

B.Protection efforts and acidic sea water.

C.Sharp decrease of whales’ populations.

D.Underwater noises by ships and industries.

3.What does the underlined word “modulate” mean in the last paragraph?

A.Produce. B.Damage. C.Balance. D.Change.

4.What can we infer from the text?

A.Man is the soul of nature.

B.Man and nature are in one.

C.Nature pardons no mistakes .

D.Nature has the final say over man.

Answer

1.A

2.B

3.D

4.B

【解析】

这是一篇说明文。文章主要介绍蓝鲸的声调调低的几个原因，这些原因都涉及到了人类。

1.细节理解题。由第二段第三句“In a study last year that analyzed more than 1 million individual recordings of whale calls, scale shifts were found across species, and among populations that don’t necessarily interact with one another.”可知，在去年一项分析了超过1百万条鲸鱼单独叫声记录的研究里，音阶变化在物种间以及种群中发现，这些种群相互之间并没有必要的沟通。由此可见，鲸鱼音调降低的情况到达了跨物种的程度。结合选项可知，选项A正确。

2.细节理解题。由第四段第一句“One possible explanation for the change is the achievements of global conservation efforts.”和第五段最后一句“Perhaps whales don’t need to be so loud because sound waves travel farther in oceans made acidic by the absorption of carbon dioxide.”可知，对于这个变化的一个可能的解释是全球保护行动的成果。也许鲸鱼不需要如此大声因为由于对二氧化碳的吸收导致海水变酸，在酸性海水中声波可以传播的更远。由此可知，鲸鱼音调的进化是由全球保护行动和酸性海水造成的。结合选项可知，选项B正确。

3.词句猜测题。由最后一段第二句“Recent study shows that, during the summer, the whales must use their top volume to be heard in the cracking ice — a natural sound increased by unnatural processes, as rising temperatures worsen ice-melt.”可知，最近研究显示，在夏天期间，鲸鱼们为了能在破冰声中被听到，必须使用它们的高音，这种破冰声是一种由温度上升恶化冰川融化的反常过程增加的自然声音。由此可见，本句中的“the impacts of a warming planet”是对前一句的“这种破冰声是一种由温度上升恶化冰川融化的反常过程增加的自然声音”的概述，星球的变暖改变了鲸鱼声音，故单词modulate表示的是改变的意思。结合选项可知，选项D正确。

4.推理判断题。由第四段第一句“One possible explanation for the change is the achievements of global conservation efforts.”，第五段最后一句“Perhaps whales don’t need to be so loud because sound waves travel farther in oceans made acidic by the absorption of carbon dioxide.”以及第六段最后一句“So the impacts of a warming planet may modulate animal sounds even in remote places.”可知，对于这个变化的一个可能的解释是全球保护行动的成果。也许鲸鱼不需要如此大声因为由于对二氧化碳的吸收导致海水变酸，在酸性海水中声波可以传播的更远。所以一个正在变暖的星球可以影响改变甚至在遥远地方的动物的声音。由此可判断，人类的保护行动，或者人类导致的二氧化碳温室效应都对动物有影响，人类和自然之间不是独立的。结合选项可知，选项B正确。