It is advised by health experts that windows should be opened now and then for air to _____, whichmakes the air in your room fresher. [ ]

Children are excited about the approach of Christmas, _____ may bring great happiness to them.

ou ever dreamed _______ in front ofthousands of people at a concert, with everyone ________ your singing.

It was in the room _________ he was born _________ the meeting was held.

There are _________200 animals in the zoo.