如图,在△ABC和△DCB中,AC与BD交于点E,且AC=BD,AB=CD.(1)求证:△ABC≌△DCB;(2)若∠AEB=70°,求∠EBC的度数.
cos150°的值为( )
下列物质属于苯的同系物的是( )
— I think so. He is a ____(有天赋的) boy.