预览页面，选词翻译弹出窗口获取语言列表时，加一个条件参数。

"is_only_can_translation":"true",

src/components/TranslateDialog.vue

@@ -113,9 +113,11 @@ export default {
      */
     getLangList() {
       if (!this.bookId) return;
-      GetLanguageTypeList({ book_id: this.bookId, is_contain_zh: 'true' }).then(({ language_type_list }) => {
-        this.langList = language_type_list;
-      });
+      GetLanguageTypeList({ book_id: this.bookId, is_contain_zh: 'true', is_only_can_translation: 'true' }).then(
+        ({ language_type_list }) => {
+          this.langList = language_type_list;
+        },
+      );
     },
 
     /**

src/views/personal_workbench/edit_task/edit/index.vue

@@ -288,11 +288,13 @@ export default {
       }
     },
     getLangList() {
-      GetLanguageTypeList({ book_id: this.courseware_info.book_id, is_contain_zh: 'true' }).then(
-        ({ language_type_list }) => {
-          this.langList = language_type_list;
-        },
-      );
+      GetLanguageTypeList({
+        book_id: this.courseware_info.book_id,
+        is_contain_zh: 'true',
+        is_only_can_translation: 'true',
+      }).then(({ language_type_list }) => {
+        this.langList = language_type_list;
+      });
     },
     /**
      * 得到我的教材课件任务列表