I READ THE BOOK, DID NOT UNDERSTAND IT. (BUT/ OR)

6 - - BAI TAP TU LUAN TIENG ANH LOP 9 UNIT 7 SAVING ENERGY
Lớp 9 BAI TAP TU LUAN TIENG ANH LOP 9 UNIT 7 SAVING ENERGY

6 - I read the book, did not understand it.

(But/ or)