每日一句口语:A man may dig his grave with his teeth.祸从口出。【知识点讲解】grave adj.重大的,重要的; 严重的; [音乐]沉重的; (颜色等)朴素的例句:Universities are facing grave problems because of diminishing resources. 由于资源的减少,大学正面临严峻的问题。