Some pre-school children go to a day-care center, __________ they learn simple games and songs.
No one can be sure _______ in a million years.
________ the decision must be made immediately requires questioning.
_______caused the accident is still a complete mystery.
________ we can’t get seems better than _______ we have.
His writing is so confusing that it’s difficult to make out ________ it is he is trying to express.