-hangbyathread;Anythingmayhappenanytime.;benotworthaday'spurchase;beinaprecariousstate--inimminentdangerofdeath;cannotkeepthewolffromthedoor;liveinconstantfearforone'slivelihood;livefromhandtomouth;nottoknowatdawnwhatmayhappenbydusk;nottoknowinthemorningwhatmayhappenintheevening;maycollapseanyday;mayfallanymoment:
makeaprecariousliving;过着朝不保夕的生活
Thepatient'sconditioniscritical.病人已朝不保夕。