If he doesn't find a solution to his problem soon, he'll surely flunk out of college.

如果他不能很快找到解决问题的办法，他肯定要被学院退学。

《柯林斯英汉双解大词典》

But just like high school, many students flunk out of college because of their poor grades.

但正如高中一样，许多大学生因成绩不好而退学。

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About 5 percent of students in the language program flunk out before their freshman year.

参加英语语言课程大约5%的学生会在上大一之前退学。

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Asked at the start of the test, if would-be motorists flunk the questions it will count as one driving fault out of the maximum of 15 allowed before a fail.

BBC: L-plate