He was so careless that he ______ being killed in the traffic accident.
—Who is the girl standing over there?—Well, if you ________ know, her name is Mabel.
You and I could hardly work together,________?
—It’s the office! So you ________ know eating is not allowed here.—Oh, sorry.
What do you mean, there are only ten tickets? There ________ be twelve.
One of the few things you ________ say about English people with certainty is that they talk a lot about the weather.