Arccos
反余弦
🗣️ 情景例句
I can't go along with you on that, I'm afraid.
恐怕在这一点上我不能认同你的廉洁。
Do you usually lenrn Japanese on Saturday?
你通常在星期六学日文吗？
Reading is only a partial solution,
看书只能解决部分问题。