No, I don't think every lesson should be fun. Some subjects, like maths or science, are just too serious or complicated to make entertaining. If teachers try to make everything fun, students might not take the lessons seriously and could get distracted. Also, not all teachers are good at making lessons fun, so it might not work for everyone.
不,我不認為每堂課都應該有趣。有些科目,比如數學或科學,實在太嚴肅或複雜,不容易變得有趣。如果老師試圖讓所有課程都變得有趣,學生可能不會認真對待課程,反而會分心。而且,也不是所有老師都擅長讓課堂變得有趣,所以這方法未必適合每個人。