step into the breach

基本解釋

This leaves central banks having to step into the breach, as they did last December when interbank rates exploded.
這使得央行不得充儅“補位”的角色，這正如去年12月銀行拆現(xiàn)問題爆發(fā)時一樣。
And even if China is shifting out of US Treasuries, it would not necessarily cause trouble in the market as long as other buyers step into the breach.
況且，就算中國對美國國債避而遠之，衹要其它買家能夠補上缺口，就未必會給市場造成麻煩。
The government’s hope has been that private firms will step into the breach as the public sector sheds jobs because of the harsh spending cuts it has announced.
這是由於政府大量減少支出，削減工作崗位數(shù)量所致。政府希望私營企業(yè)能夠填補這個缺口。

Yemen's student-led opposition says it is ready to step into the breach when Mr Saleh goes.
ECONOMIST: But who will replace the president?
If the Justice Department is compromised (and the Clinton one is), Congress should step into the breach.
FORBES: Fact and Comment
As the Administration appears incapable of resisting Pyongyang's stratagems, it behooves the Congress step into the breach.
CENTERFORSECURITYPOLICY: Center For Security Policy

If you step into the breach, you do someone else's work when they are unable to do it.