—How did she get infected? —She _______ the viruses without any protection.
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.
_____you I owe a thousand apologies____ having doubted your ability.