—May I have a glass of beer, please?—Beer? There is _______ left, but you can have some orange juice.
We all know the truth ___ there are air, water and sunlight there are living things.
It ________ Bob drives badly.
Is this ________ we met each other two years ago
"Do you know ________ " "His father is a doctor."
I have no idea ________ or not he has finished the work.