_______ we are doing has never been done before.
He’s got himself into a dangerous situation ________ he is likely to lose control over the plane.
What surprised me was not what he said but _______ he said it.
—Sorry to hurt you.—_______. You didn’t mean to, did you?
Whenever you enter the reading room, you can find all the students _____ at their desks, with their attention _____ on the books, except Tom.
Tom joined a dancing group but didn’t seem to , so he left.