A) Learn
B) To learn
C) Learning
D)
A) Leave
B) To leave
C) Leaving
D)
A) Had better
B) Can
C) Must
D)
A) Don’t have to
B) Can not
C) Must not
D)
A) Can’t
B) Couldn’t
C) Might not
D)
A) Must
B) Must be
C) Must have been
D)
A) Can you
B) Are you able to
C) Might you
D)
A) Can’t
B) Shouldn’t
C) Don’t have to
D)
A) Can’t
B) Won’t be able to
C) Couldn’t
D)
A) Might
B) May
C) Would
D)
A) Must be costing
B) Must cost
C) Must have cost
D)
A) Would float
B) Would be floating
C) Would have float
D)
A) Can
B) Had better
C) Has to
D)
A) Could be turning
B) May turn
C) Can be turned
D)
A) Had better
B) Might
C) Have got to
D)
A) Couldn’t
B) Mustn’t
C) Don’t have to
D)
A) Don’t can
B) Can’t
C) Can not
D)