[单选题]如何显示这样一个边框:上边框10像素、下边框5像素、左边框20像素、右边框1像素()A . border-width:10px5px20px1pxB . border-width:10px20px5px1pxC . border-width:5px20px10px1pxD . border-width:10px1px5px20px
[判断题]数字相机总像素比有效像素低。( )A.对B.错
[判断题]数字相机总像素比有效像素低。( )A.对B.错
[单选题]像素比是指一个像素长和宽的比例,PAL制模拟电视为矩形像素,其像素长宽比为()。A . 4/3B . 16/9C . 9C.16/15D . 16/14