—Who’s knocking at the door?—Maybe        wanting to sell some new products.

____ is our belief that improvements in health care will lead to a stronger, more prosperous economy.

I couldn’t help ______if the bus was late.

--__________must be working in the office, I think. --Sure, the light is still on.

---- Who knocked at the door?  ---- I’ve no idea. I just pretended nobody was at home, so I didn’t ask who was___.