Exercise:Use: will/won´t,may/might

A: When will my photos be ready?
B: They probably _________take very long.
    Two hours at the most, so they ________
    definitely be ready by four o´clock.
A: How much ________they cost?
B. Ten punds probably. But they _________
     be a little more.It depends.
A: I________try to be back at two to pick them
    up. But I_________be a bit late.