Although he is more serious ( ) his studise than I am ,my grades are better than his .A withB for c.about.D at为什么选c,

Although he is more serious ( ) his studise than I am ,my grades are better than his .A withB for c.about.D at为什么选c,
Although he is more serious ( ) his studise than I am ,my grades are better than his .A with
B for c.about.D at
为什么选c,

Although he is more serious ( ) his studise than I am ,my grades are better than his .A withB for c.about.D at为什么选c,
be serious about对.严肃认真
尽管他对于学习的态度比我认真,但是我的成绩比他高.

固定搭配，这里be serious about是对···认真的意思。

固定搭配 你应该多记一些 这些东西没有很具体的原因 就行1加1等于2 一样