prevent;deter;guard against;avoid;keep off;fend off ～矛盾激化prevent contradictions from becoming more acute/～污染prevent pollution/～传染keep off infection of a disease/～事故forestall accidents/～通货膨胀和防范金融风险fend off inflation and financial risks/～吸毒avoid drug addiction /～一哄而上guard against rash action/～战争prevent war