开卷

to open a book / open-book (exam)

to open / to start / to turn on / to boil / to write out (a prescription, check, invoice etc) / to operate (a vehicle) / carat (gold) / abbr. for Kelvin, 開爾文|开尔文[Kai1 er3 wen2] / abbr. for 開本|开本[kai1 ben3], book format

to roll up / roll / classifier for small rolled things (wad of paper money, movie reel etc)

scroll / book / volume / chapter / examination paper / classifier for books, paintings: volume, scroll

to roll (up) / to sweep up / to carry on / roll

to roll up / to sweep up; to carry along / a roll / classifier for rolls, spools etc

lit. opening a book is profitable (idiom); the benefits of education