3个选择题...急!He ____ the exam by the end of last month.A has pa

3个选择题...急!
He ____ the exam by the end of last month.
A has passed
B had passed
C was passed
D passed
This problem is _______ for such a little girl to solve.
A such difficult
B difficult enough
C far too difficult
D too far difficult
If he goes to the cinema tomorrow,______.(请分别解释一下,谢谢)
A so will i
B so i will
C so i do
D so do i