留级的英文：
fail to go up to the next grade
- He had to repeat the fourth grade.
他读四年级时留级一年。 - Academic Failure: “Social Promotion” Versus Retention as Education Policy
学业失败:“社会性升级”与教育政策留级之争
n. 不及格
v. 失败，不及格；破产；缺乏；衰退
- If you fail to plan, you plan to fail.
如果你不做计划，那就是在计划着失败。 - The download failed.
下载失败。 - Intelligent as you are, I suspect you will fail.
尽管你聪明，我还是猜想你会失败。 - Their attempt to restore the king failed.
他们想使国王复位的企图失败了。 - They failed to bridge the chasm.
他们未能跨越这道鸿沟。
n. 年级；阶段；等级
v. 将…按级别分类；给…批分数，改作业；混合
- longitudinal grade
纵坡度 - There are lots of jobs in junior grades.
初级阶段有很多工作要做。 - Red grades into pink.
红色逐渐变成粉红色。 - The teachers are grading the papers.
老师们正在给卷子打分数。 - Pencils are graded according to softness.
铅笔根据硬度分类。