Improve exam flow and WebGL build

Build/index.html

@@ -59,9 +59,9 @@
       var buildUrl = "Build";
       var loaderUrl = buildUrl + "/7a2dbded24d57e056180125b1583e7c4.loader.js";
       var config = {
-        dataUrl: buildUrl + "/d1e2d1e3e120229ced20d8237eae353c.data.gz",
-        frameworkUrl: buildUrl + "/62981e01aece13a94bac539c85228c75.framework.js.gz",
-        codeUrl: buildUrl + "/e89ebbd31642308ad16cecffa889584e.wasm.gz",
+        dataUrl: buildUrl + "/1ffb9ec7407d7ad0a61ab4035c55d23d.data.gz",
+        frameworkUrl: buildUrl + "/360830ff1fc916f53a94ba2fa3fd0d8f.framework.js.gz",
+        codeUrl: buildUrl + "/fcc5cc41937245b03571180d2961701c.wasm.gz",
         streamingAssetsUrl: "StreamingAssets",
         companyName: "DefaultCompany",
         productName: "运动伤害现场急救虚拟仿真实验",
@@ -69,14 +69,6 @@
         showBanner: unityShowBanner,
       };
 
-      config.cacheControl = function (url) {
-        if (url === config.dataUrl || url === config.frameworkUrl || url === config.codeUrl) {
-          return "immutable";
-        }
-        return "must-revalidate";
-      };
-      config.devicePixelRatio = Math.min(window.devicePixelRatio || 1, 1.5);
-
       // By default Unity keeps WebGL canvas render target size matched with
       // the DOM size of the canvas element (scaled by window.devicePixelRatio)
       // Set this to false if you want to decouple this synchronization from