Poisson's equation
[化] 泊松方程
🧩 词语组成解析
🗣️ 情景例句
If you're under twenty-one years of age ...
如果你还不到二十一岁……
The healthful man can give counsel to the sick.
健康的人可以对生病的人提出忠告。
Let us suppose that a child suddenly crosses the road in front of you.
让我们假设一个小孩子突然在你前面穿过马路。