19.Vitamin D helps our bodies make a special chemical, and this special chemical,________,affects our brains, making us feel happy.
I was giving a talk to a large group of people, the same talk I _______ to half a dozen other groups.
“You’ve left the light on.” “Oh, so I have. _____ and turn it off.”
He has changed a lot. He _______ not what he _______.
“I suppose you _________ that report yet?” “I finished it yesterday, as a matter of fact.”
—The dinner was delicious! —I agree. I’m so full. —That’s too bad. But some dessert ______.