fall behind

fail to keep up落后;跟不上John fell behind in his studies and finally had to leave school.约翰学习跟不上,最后只好退学。

To be promoted or to fall behind is not a matter of salary but even more a matter of selfrespect.升职或者落后不仅仅是薪金的问题,更重要的是自尊。

I don't want to fall behind in my studies.在学习上我不想落伍。

Diligence helps one to go forwardwhere as laziness makes one fall behind.勤奋使人上进,懒惰使人落后。