Variation problem
[计] 变分问题
🧩 词语组成解析
🗣️ 情景例句
I've got plenty of time.
我有的是时间。
I can see the brown wall of dust coming toward us with the wind.
风卷起褐色的墙壁似的滚滚黄沙，向这里袭来。
It is one of the most unpleasant discoveries which we all make that we must decline in this way,
人人必然会衰老。