已知:如图.EF为梯形ABCD的中位线.AD=AN.连接DN交EF于点M.AM的延长线交BC于点H.连接DH.NH(1)给出以下结论:①AH⊥DN,②AD⊥DH,③HM=MN,④DH=NH你认为正确的结论是①④①④.中的一个正确结论加以证明.
摘要: PROBLEM TO BE SOLVED: To provide a polarizer capable of exhibiting the polarizing characteristic when used in an environment of strong ultraviolet light and preventing absorption of display light emission in an environment of weak ultraviolet light....