Tractrix
等切面曲線, 曳物線
??? 情景例句
350 yuan? Are they real?
350元？是真表嗎？
Marry in lent,and you'll live to repent.
借債結(jié)婚，一生悔恨。
Brevity is the soul of wit.
簡(jiǎn)潔是智慧的精華。