——There must be a dozen pens in this house but I can never find one when I need one.——Keep looking. is sure to turn up.
I wonder ____ we can solve this hard problem.
---Would you please give him the paper the moment he ____? --- No problem.
____ is mentioned above, the number of the cattle here has been limited to 200.
--- Any phone call for me? --- Yes.____ telephoned 10 minutes ago.
"No, no ", he whispered,____ talking to himself.