Commutative system
[计] 可交换系统
🧩 词语组成解析
a. 交替的, 交换的\\n[法] 交换的, 代替的, 互相的
🗣️ 情景例句
I'll have chocolate.
我要巧克力的。
I usually get up at 8 o'clock.
我通常8点起床。
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。