问题补充：
I think Maths is of all my subjects.
A. much difficult one
B. difficult one
C. most difficult one
D. the most difficult one
答案：
A. much difficult one
B. difficult one
C. most difficult one
(答案→)D. the most difficult one
解析：句意:我认为数学是所有的科目中最难的。因为all表示的是三者以上的范围做比较，所以用最高级的形式，最高级往往与定冠词the连用。故选D。
