11.   She popped her head back in, and widened her eyes innocently.

12.   Just then Victoria popped her head in.

13.   Amy popped her head round the door to tell Kathleen that they had found some ID on the track and the police had brought his parents in.

14.   As if on cue, one of them popped his head out of the water and swam in front of the boat.

15.   A U.S. soldier, unaware he is being watched, briefly pops his head out of a foxhole.

16.   Every now and then, the members of a friendly chorus of Greek peasants pop their heads over the walls to echo her.

17.   Executive assistant Amanda Kingery pops her head in the door.

18.   His mother said she popped her head in his room once, saw the folded clothes and figured he was outside playing.

19.   In a pedestrian walkway behind Colorado Boulevard, Tom Welsh popped his head out from a sleeping bag.

20.   Jack and Chuck popped their heads over the backyard fence.