Arctangent
反正切
🗣️ 情景例句
Why are you back so early?
你们怎么这么早回来？
And they are very proud of their son's success in getting a scholarship to Harvard.
他们为儿子获得哈佛的奖学金页感到非常自豪。
punctuated by textbooks----those purchasable wells of wisdom----
并以教科书-那些可以买到的智慧源泉-予以强化，