手机彩票网
<tr id='SXZHcQ'><strong id='SXZHcQ'></strong><small id='SXZHcQ'></small><button id='SXZHcQ'></button><li id='SXZHcQ'><noscript id='SXZHcQ'><big id='SXZHcQ'></big><dt id='SXZHcQ'></dt></noscript></li></tr><ol id='SXZHcQ'><option id='SXZHcQ'><table id='SXZHcQ'><blockquote id='SXZHcQ'><tbody id='SXZHcQ'></tbody></blockquote></table></option></ol><u id='SXZHcQ'></u><kbd id='SXZHcQ'><kbd id='SXZHcQ'></kbd></kbd>
了解几何光学原理，利用凹面镜成像原理，当把影像放到凹面镜二倍焦距处，在空中呈现出等大逼真的立体像，所成影像具备较高的↑清晰度、立体感和真实感，使其"看得见、摸不着"。
