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页上边的空白
🗣️ 情景例句
Where did the time go?
时间溜的真快！
A man without a friend is only half a man.
无友的人只能算半个人。
and we have only to turn to that extraordinary discovery of echo-location in bats to see a case in which the voice plays a strictly utilitarian role.
我们只要看一看蝙蝠回声定位这一极不寻常的发现，就可以探究一下声音在什么情况下有绝对的实用价值。