The word “they” in paragraph 2 refers to___________ A. machines B. grading softwares C. essays D. classroom activitiesĐoạn văn48/50The word “they” in paragraph 2 refers to___________machines grading softwaresessays classroom activitiesGiải thíchB They quy chiếu cho grading softwares:phần mềm tính điểm