Why __ practice again and again?
Many people have been ill from a strange disease these days,_________ we’ve never heard of before.
The sunlight came in____________ the windows in the roof and lit up the whole room.
She stepped into the bedroom quietly_________she might wake up her roommates.
—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.