Arithmetic series
等差级数
🧩 词语组成解析
🗣️ 情景例句
Would you prefer a window, aside or enter seat?
您喜欢靠窗、靠走道还是中间的位置？
The pen is mightier than the sword.
文能胜武。
There he was picked up by a policeman and sent back to England by the local authorities.
他在那儿被一个警察抓住了，之后被当局送回了英国。