一道完形填空里的题 There he put his name down for world geogarphy,( ) after the first day,he did not go to class any more.
括号里是填but 还是 however ( 答案是but)
请回答：
请问这道题和什么知识点有关?（例如：连词,插入语等）
还有,能不能详细讲一下but 和 however 的差别（原创）
They had not trained hard,however they won.