Operator equation
[计] 算子方程
🧩 词语组成解析
🗣️ 情景例句
The welcome sign over the door.
门上的欢迎标语。
How long does it take for a letter to get to California ?
一封信到加利福尼亚要花多长时间？
The operation, which lasted for over four hours, proved to be very difficult because of the hard resin which covered the skin.
手术持续了4个多小时，非常难做，因为皮肤上覆盖着一层硬硬的树脂。