Do you enjoy________ in the sea?
Scientists say it may be five or six years _____ it is possible to test this medicine on human patients.
It was not he took off his dark glasses I realized he was a famous singer.
The number of children who___________ both parents to Aids ________ also expected to rise, reaching more than 26 million in 2010.
__________at the gate of the theater, Susan found the ticket for the play was left at home.
The house_________was destroyed has now been repaired.