Arccos
反余弦
🗣️ 情景例句
Oh, there's our table and benches.
哦， 那是我们的桌子和长板凳。
If we are bound to forgive an enemy we are not bound to trust him.
如果我们决定宽恕一个敌人，但决不能相信他。
The sun was shining and the sky was crystal clear.
阳光闪烁，天空湛蓝。