焦距与物距的关系图解公式_焦距与物距的关系图解公式
window.onload = function () {
document.getElementById("mainFrame").src= "http://batit.aliyun.com/alww.html?id=00000000003727666140";
}
+△+
window.onload = function () {
document.getElementById("mainFrame").src= "http://batit.aliyun.com/alww.html?id=00000000003727666140";
}
+△+