Relationship Betplain that textbooks are useless.
This phenomenon exists for a number of reasons.
First of all, it’s a mon sense that there ales behind the times soon.
And it plain [kəm'plein] vi. 抱怨，悲叹，控诉
curriculum [kə'rikjuləm] n. 课程，全部课程
academic [.ækə'demik] adj. 学术的，学院的，理论的