from beginning to end是习惯用法,即自始至终,不要加冠词,但如单独使用则要加冠词,例如:At the beginning,the teacher gave us an exam. [误] They study hard in the class from the beginning to the end. [正] They study hard in the class from beginning to end. [析] from beginning to end是习惯用法,即自始至终,不要加冠词,但如单独使用则要加冠词,例如:At the beginning,the teacher gave us an exam.