多项选择题
A.E(c)=cB.E(c)=0C.E(cX)=cE(X)D.E(cX)=c2E(X)E.E(a+bX)=bE(X)
A.Scenic spots in Paris.B.A business trip.C.Whether to go to Paris or London.D.Where to spend their holiday.
A.瓦斯检查员配备数量不足B.不按规定检查瓦斯,存在漏检、假检C.井下瓦斯超限后不采取措施继续作业D.瓦斯超限后停止作业的