Nabla
纳布拉琴, 劈形算符(数学符号), 微分算符[子]
🗣️ 情景例句
Mrs. Greenberg is on the phone.
Greenberg太太打电话来。
What is learnt in the cradle lasts (or is carried) to the grave.
小时学会的事情到老不会忘记。
In primitive cultures the obligation to seek and to receive the traditional instruction is binding to all.
在原始文化中，寻求和接受传统教育的义务对全民都有约束力。