swot up (something)
phrasal verb with swot verb [ I ] UK informal or child's word uk/swɒt/ us/swɑːt/ -tt-
（尤指在考试前）刻苦学习，用功复习
to learn as much as you can about a subject, especially before an exam
She's at home, swotting up on her maths. 她在家埋头复习数学。