Perfective maintenance
[计] 完善性维护
🧩 词语组成解析
a. 完成的, 完成时的\\nn. 完成时
🗣️ 情景例句
He knows all there is to know,
他无所不知，
Don't believe him.
不要相信他。
He's picking the apples on that tree. He's putting them in a basket.
他在摘那棵树上的苹果。他正在把苹果放进一只篮子里。