英文iq題～～plx help

(1)What can you break without touching it?
(2)What goes up and down but doesn't move?
(3)What time is the same spelled backward or forward?
(4)What word if pronounced right is wrong but if pronounced wrong is right?

(1)pr_ _ _ _ _
(2)st_ _ _ _
(3)no_ _
(4)wr_ _ _