Permutoid
[化]交换体
🗣️ 情景例句
You don't know what the surprise is yet?
你们还不知道这个惊喜是什么？
How far is it from the shore of the Atlantic to the mountains?
从大西洋海岸到山脉有多远？
My grammar is improving, but I find idioms and useful expressions hard to learn.
我的语法在进步，但我发现习语和有用表达很难学。