Substr
n. [数]子串函数；[数]字符截取函数；[数]取字符串的子串
🗣️ 情景例句
As a matter of fact,
事实上，
Do not swap horses when crossing a stream.
处在危难中，不宜大更动。
I had one after my lunch.
我是在饭后喝的。