According to the latest research, getting enough sleep is _____ to maintaining good health and reducing stress.
_____ is even important _____ as the earth cooled down, water began to appear on its surface.
I don’t think she will come to the meeting on time, ______?
We don't imagine the twins have arrived, _____?
Mother said that Mike could eat two of ten oranges and that the rest _______ left for Tom and Betty.
One-third of the country _____ covered with trees and the majority of the citizens _____ black people.