Arccos
反余弦
🗣️ 情景例句
Hi, Marilyn.
嗨 Marilyn。
To swing
打秋千
Those who seek it undertake an arduous journey and can never be sure that they will find it.
那些寻求正义的人走的是一条崎岖的道路，从来没有把握他们最终将到正义。