题目18.单选题(5分)已知事件A=|2,3,4,5,6|,事件B=|4,5,6,7|,则A-B=().A. 3,4,5B. 3,5,7C. 2,3D. 3,518.单选题(5分) 已知事件$A=|2,3,4,5,6|$,事件$B=|4,5,6,7|$,则$A-B=()$.A. 3,4,5B. 3,5,7C. 2,3D. 3,5题目解答答案C. 2,3