Arccos
反余弦
🗣️ 情景例句
I'm not quite familiar with the claim and arbitration in international trade.
我对国际贸易的索赔与仲裁不够熟悉。
It is one thing to speak much and another to speak pertinently.
话讲得多是一回事，讲得恰当是另一回事。
New York is built on a group of islands on the east coast of the USA at a point where several rivers flow into the ocean.
纽约市建立在美国东海岸的一群岛屿上，那儿是好几条河流入海的交汇点。