调整“查看答题报告”按钮的出现时间，即所有题目做完后才出现

src/views/book/courseware/preview/components/video_interaction/VideoInteractionPreview.vue

@@ -24,7 +24,7 @@
     </div>
     <!-- v-if="Object.keys(this.userAnswer).length === data.file_info_list.length" -->
     <el-button
-      v-if="data.property.feed_back === 'total'"
+      v-if="data.property.feed_back === 'total' && answerNumber === data.file_info_list.length"
       type="primary"
       :style="{
         background:
@@ -128,6 +128,7 @@ export default {
         rightRate: 0,
       },
       player: null,
+      answerNumber: 0, // 用户答题个数
     };
   },
   watch: {
@@ -253,6 +254,7 @@ export default {
         this.visible = false;
         this.player.play();
       }
+      this.answerNumber = Object.keys(this.userAnswer).length;
     },
     lookReport() {
       this.player.pause();