Four operations
四则运算
🧩 词语组成解析
four
[fɔr]
num. 四;四个;第四;
n. 四的;四个一组之物;
n. 运作；运营；业务操作（operation的复数）
🗣️ 情景例句
I did , but everything is OK,so I decided to come back.
回去了， 但一切安好。于是我决定回来。
How about Mary? How long has she lived there?
玛丽怎么样？她在那儿住多久了？
What are you doing?
你在干什么？