Not all sounds made by animals serve as language, and we have only to turn to that extraordinary discovery of echolocation (回声定位) in bats to see a case in which the voice plays a strictly practical role.To get a full appreciation of what this means we must turn first to some recent human inventions. Everyone knows that if he shouts near a wall or a mountainside, an echo will come back. The further off this solid obstacle, the longer time it will take for the return of the echo. A sound made by tapping on the main body of a ship will be reflected from the sea bottom, and by measuring the time interval between the taps and the receipt of the echoes the depth of the sea at that point can be calculated. So was born the echo-sounding equipment, now in general use in ships. Every solid object will reflect a soundThe main purpose of this passage is to____!A. describe that animals can make different soundsB. prove that animals voices can play practical rolesC. inspire the readers to make more inventionsD. startle the readers with some shocking facts
Not all sounds made by animals serve as language, and we have only to turn to that extraordinary discovery of echolocation (回声定位) in bats to see a case in which the voice plays a strictly practical role. To get a full appreciation of what this means we must turn first to some recent human inventions. Everyone knows that if he shouts near a wall or a mountainside, an echo will come back. The further off this solid obstacle, the longer time it will take for the return of the echo. A sound made by tapping on the main body of a ship will be reflected from the sea bottom, and by measuring the time interval between the taps and the receipt of the echoes the depth of the sea at that point can be calculated. So was born the echo-sounding equipment, now in general use in ships. Every solid object will reflect a sound The main purpose of this passage is to____! A. describe that animals can make different sounds B. prove that animals voices can play practical roles C. inspire the readers to make more inventions D. startle the readers with some shocking facts
题目解答
答案
我们来逐步分析这篇短文，并找出它的主旨。
一、通读全文，理解大意：
这段文字主要讲的是：
- 并不是所有动物发出的声音都具有语言的功能。
- 以蝙蝠的回声定位为例，说明动物的声音可以有实用功能。
- 为了更好地理解这一点，作者先介绍了一些人类发明，比如回声测深仪（echo-sounding equipment）。
- 回声测深仪的原理是：通过测量声音从发出到反射回来的时间，来计算水深。
- 然后指出，蝙蝠也利用类似原理（回声定位）来导航和捕食，说明声音在动物中也可以有实际用途，而不只是语言交流。
二、分析选项：
A. describe that animals can make different sounds
（描述动物可以发出不同的声音）
→ 虽然文章提到了动物的声音，但重点不是“不同种类的声音”，而是“声音的实用功能”。排除。
B. prove that animals voices can play practical roles
（证明动物的声音可以发挥实用作用）
→ 这正是文章的主旨。文章通过蝙蝠的回声定位，说明动物的声音可以用于导航、探测环境等，是实用的工具。保留。
C. inspire the readers to make more inventions
（激励读者发明更多东西）
→ 虽然文章提到了人类的发明，但目的是为了类比说明动物声音的实用功能，不是鼓励读者去发明。排除。
D. startle the readers with some shocking facts
（用一些令人震惊的事实吓到读者）
→ 文章语气平和，没有“吓人”的意图，只是客观描述。排除。
三、结论：
文章通过蝙蝠的回声定位，说明动物的声音可以有实际用途，而不只是语言交流。这是文章的主要目的。
✅ 正确答案是：
$\boxed{B}$
解析
考查要点：本题主要考查学生对文章主旨的把握能力，需要通过具体细节理解作者的写作意图。
解题核心：文章通过人类发明的回声测深仪与蝙蝠的回声定位进行类比，说明动物的声音不仅用于交流，还能发挥实际作用。
关键思路：明确文章的核心对比对象（人类发明与动物行为），抓住“实用功能”这一核心概念，排除干扰选项。
选项分析
A. describe that animals can make different sounds
文章虽然提到动物会发出声音，但重点并非声音的多样性，而是声音的实用功能（如蝙蝠的导航）。因此此选项偏离主旨。
B. prove that animals' voices can play practical roles
文章通过回声测深仪与蝙蝠回声定位的类比，明确说明动物的声音可以用于实际目的（如探测环境、捕食）。此选项直接对应文章核心意图。
C. inspire the readers to make more inventions
文章仅以人类发明为例说明动物行为的科学性，并非鼓励发明，因此此选项过度解读。
D. startle the readers with some shocking facts
文章语气平和，无“震惊”意图，仅客观介绍科学现象，故此选项不符合文风。