brush up

擦亮；重新学习；复习

browbeat, browbeaten, brown, brown bread, brown paper, brown sugar, brownie, browning, brownish, browny, brownstone, browse, bruise, bruiser, bruit, brunch, brunette, brunt, brush, brush aside, brush off, brush-off, brush-up, brushing, brushstroke, brushwood, brushwork, brusque, brusquely, brusqueness, Brussels, Brussels sprout (also sprout), brutal, brutality, brutalize, -ise, brutally, brute, brutish, brutishly, BS, BSc,