fall by the wayside

半途而废, 中途退出

例句与用法：

The major world powers are afraid of falling behind in the arms race.

世界各大强国均惟恐在军备竞赛中落後。

France has fallen behind (Germany) in coal production.

法国在产煤方面落後(於德国)了。

I've fallen behind with my correspondence.

我积压了许多信没回。

Don't fall behind with the rent, or you'll be evicted.

不要逾期不缴房租，否则会被逐出。

详细释义：

因失败而放弃

We must care for the weak who would otherwise fall by the wayside.

我们要关心那些弱者, 不然他们会因失败而放弃努力的。