[brush up] vt (ca. 1600) 1: to improve or polish as if by brushing
2: to renew one's skill in "brush up your Spanish" ~ vi: to refresh one's memory: renew one's skill "brush up on math" -- brush.up n
[brush up] vt (ca. 1600) 1: to improve or polish as if by brushing
2: to renew one's skill in "brush up your Spanish" ~ vi: to refresh one's memory: renew one's skill "brush up on math" -- brush.up n
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012