Permutoid
[化]交换体
🗣️ 情景例句
How many stops will the train make on the way?
路上火车停几站？
Diseases come on horseback, but go away on foot.
病来如山倒，病去如抽丝。
By bicycle? From Beijing? That's a long trip.
骑自行车去？从北京出发？这可是长途旅行呀。