她担心会挂掉化学课，所以每天努力学习。

She was afraid she would ___flunk chemistry, so she studied hard every day.

老师因为考试作弊给那个学生打了不及格。

The teacher ___flunked the student for cheating on the exam.

他因为没复习功课，所以考试不及格了。

He ___flunked the exam because he didn't study.