polish up

• • 擦亮；磨光；由于摩擦而变得光亮：

    He polished up the old copper coins.

    他把古铜币擦得锃亮。

  • [口语]改进；润色；修饰：

    He wants to go to evening classes to polish up his English.

    他想上夜校补习英语。