Epimeric
差向异构体的
🗣️ 情景例句
Oh. I'm sorry.
噢，对不起。
Easier said than done.
说时容易做时难。
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。