It was problem that of the students could work it out.
You can stay here , _______ you can leave at once.
.----I’d like a cup of black coffee. What about you, Maggie? --- I prefer coffee______ sugar.
They thought ________ important to look left and right when ________ the road.
The guide said that much attention must __________ these details.
He couldn’t ________an answer when I asked him why he was late.