Sometimes I wonder ______ that has made me feel differently from the others.
She stepped into the bedroom quietly_____she might wake up her roommates.
Many people have been ill from a strange disease these days,_____ we’ve never heard of before.
—He_____ to the meeting. Have you informed him of it? —Sorry. I_____ to.
It is not enough only_____the rules of grammar if you want to learn English well.
He_____the person referred to be put in prison.