单项选择题
A、 fp=fopen("Demo", "r"); B、 fp=fopen("Demo", "ab+"); C、 fp=fopen("Demo", "w+"); D、 fp=fopen("Dem0", "r+")
A、 1,2,3,4,5,6,7,8,9,10, B、 10,9,8,7,6,5,4,3,2,1, C、 1,2,3,8,7,6,5,4,9,10, D、 1,2,10,9,8,7,6,5,4,3,