The most popular extra (额外的) classes at my school were piano lessons and drama club.Both classes offered exams students
问题描述：
The most popular extra (额外的) classes at my school were piano lessons and drama club.Both classes offered exams students could take.
这里的could Both classes offered exams students could take
答
could 是can 的过去式
Both classes offered exams students could take =>Students could take exams that two classes offered
学生能参加这两门课提供的考试