Because the highway system was built 40 years ago , most of the roads now need to repair45/50Mark the letter A, B, C, or D on your answer sheet to show the underlined part that needs correction Because the highway system was built 40 years ago , most of the roads now need to repair. Becausewas builtmost ofto repairGiải thíchĐáp án D To repair => repairing hoặc to be repaired