A.You can't.
B.No one uses it.
C.I am afraid you can't.
D.Who told you?

A.Yes, he is not in at the moment. 
B.No, you can't. 
C.Yes, this is Brown speaking.
D.Sorry, speaking.

A.No, they are mine.
B.No, you can't. 
C.Sure. 
D.Yes, you can.

A.Sure.
B.No, you can't.
C.No, they are mine.
D.Yes, you can.

A.I don't mind 
B.It doesn't matter
C.You do it please 
D.Go ahead

A.I don't mind
B.It doesn't matter
C.You do it please
D.Go ahead

A.No, you can't do it
B.Sorry, but you may not
C.Well, I am afraid I am going to use it myself
D.Of course not. I'm going to need it myself

A.Yes. you need  
B.Yes. ask
C.Yes. please
D.Let me see

A.is 
B.are 
C.was 
D.were

A.went  
B.had gone
C.has gone 
D.goes

A.climb 
B.climbing
C.to climb
D.climbed