The U.S.government says Tehran is trying to make weapons-grade nuclear material.

VOA: standard.2010.06.29

If the student hasn't mastered the basic concept, we will make sure that the grade scheme gives a failing grade.

如果学生没有掌握基本的概念，我们会确保,成绩将会不及格。

麻省理工公开课 - 固态化学导论课程节选

They want to make the tests for the... they get into another grade, a little harder.

他们想通过考试……让孩子们升入下一个年级，并提升一点考试难度。

哈莱姆的变迁 - SpeakingMax英语口语达人