Petromyzoniformes
七鳃鳗目
🗣️ 情景例句
But as exporters of a complete plant,
但是，作为成套设备出口商，
Good medicine tastes bitter.
良药苦口。
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。