fall down
be shown to be false or inadequate; collapse 显示不实或不足; 崩溃; 失败
The plan fell down because it proved to be too expensive. 这项计划因费用过高而告吹. fall down on sth (infml 口) fail to do sth properly or successfully 没有把某事做好
fall down on one´s promises 未履行自己的诺言
He fell down on the job. 他未能把这件工作做好.