Most whales must come up for air after several minutes, _______ a few can stay under water for an hour or more.
— Where is my English book? — I brought it to you _____you were in hospital yesterday afternoon.
The nutrients in _____falls into the ocean quickly become available to other living creatures.
Don’t forget where the emergency exits are _____an emergency.
The lake is calm and clear, and one of the things that _____in the water is the famous tower.
The roommates have lived for three years and not once _____with each other.