Permutoid
[化]交換體
??? 情景例句
I've been working too hard. I'm beat.
我工作的太多，我快垮了。
The leftover food began to smell bad.
剩飯開始發臭了。
always assuming,of course, that the sea is calm.
當然，這一切只有在大海風平浪靜的情況下才有可能。