Arccos
反余弦
🗣️ 情景例句
The more natural it will become.
它们就会变得越自然。
Many hands are better than one.
众擎易举。
The next time you see a watch, look at the back. You may see the English words Made in China.
下次你瞧见一块手表是，瞧瞧它的背面。你也许能看到“中国制造”的英语字样。