.__________,it is our duty to learn our lessons well,as students.
问题描述：
.__________,it is our duty to learn our lessons well,as students.
__________,it is our duty to learn our lessons well,as students.
A.As usual B.To some degree C.More or less D.On a personal note
请问为什么只能选D
答
on a .note以一种.调子,口气(说话）On a personal note可以灵活理解为“就我个人（观点）而言”或者“私下说”
这个地方“学生就应该把书读好”是一种观点,选D符合这种语气和意义.
as ususal,像往常一样,是该用于谈及某种经常或反复发生的事.
to some degree,在某种程度上,用于谈及对于话题内容部分赞同或坚持.
more or less通常应该是修饰形容词或者副词之类,但一般应该不能单独放在句首,作为一种引出话题或后问的结构.
综上所述,只有D合适.