She said she was glad the difficulty had been _____.
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.