brush up on

• 温习

brush up on的用法和样例：

例句

1. He brushed up on fractions before taking the arithmetic test.
   在参加算术考试前他又重温了分数。
2. I'm brushing up on my French at adult school just to surprise them.
   我正在成人学校补习法语，到时好让他们大吃一惊。