Quadratic variational problems
[计] 二次变分问题
🧩 词语组成解析
a. 二次的\\nn. 二次方程式
a. 变异的
n. 问题；难题（problem的复数）
🗣️ 情景例句
I did drink a lot of coffee when I was younger, But I have noticed the health benefits since I quit.
我在年轻时确实喝过很多咖啡，但我发觉戒了咖啡后身体健康多了。
Call a spade a spade.
据实而言。
Most of the earth's surface is covered by water.
大部分的地球表面被水覆盖着。