1.---Haven't you been told that Jack's father is a millionai

1.---Haven't you been told that Jack's father is a millionaire?
---_____?He would refuse any help from his father,even if it were offered.
A.So what B.What for C.Pardon D.How come
2.______,and the problem could be solved.
A.So long as you keep up your courage
B.A bit more effort
C.If you make your efforts
D.Sparing no efforts
3.---David,will you start your own business after graduation?
---Mm,it's not been decided yet.I _______ further my study for a higher degree.
A.need B.must C.would D.might