Lettsomite
绒铜矿
🗣️ 情景例句
OK, what do you need most of all?
好， 你们最需要的是什么？
Where were you born?
你出生在什么地方？
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。