We cannot afford to drop behind our competitors.

我们可担当不起落后于竞争对手的后果。

Her long illness caused her to drop behind the rest of the class.

她长期生病，所以落后于别的同学。

Don't drop behind in your work.

在工作上不要落后。

This is also true with those who temporarily drop behind .

这对那些暂时落后的人来说也是适用的。

Herr long illness caused her to drop behind the rest of the class.

她长期生病使她落后于班上的其他同学。