Difference operator
[计] 差分算子
🧩 词语组成解析
🗣️ 情景例句
and just enjoy this beautiful spring day.
尽情享受这美好的春天。
God defend me from my friends; form my enemy I can defend myself.
防友靠天，防敌靠己。
It was no use pretending that I had not seen him, so I waved to him.
若再装作没看见他已是没有用了，我只好向他招手。