【CSS3】Advanced8：CSS Backgrounds: Multiples, Size, and Origin

1.Multiples,Size,and Origin

 eg:background-image:url(bg.png),url(bullet.png) 0 50% no-repeat,url(arrow.png) right no-repeat

background-image

background-color

background-position

background-size:auto length percentage  contain cover

background-repeat

backgound-origin:border-box padding-box conten-box

backgound-clip

background-attachment