只有预览选词翻译才需要这个参数

src/components/CommonPreview.vue

@@ -376,7 +376,6 @@ export default {
       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;
       });

src/courseware_preview/index.vue

@@ -459,7 +459,6 @@ export default {
       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;
       });

src/mobile_preview/index.vue

@@ -266,7 +266,6 @@ export default {
       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;
       });

src/web_preview/index.vue

@@ -790,7 +790,6 @@ export default {
       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;
       });