Lots of trees ________in our city over the years. It is becoming greener and greener!
--______ do you stay up late? -- Never. I always go to bed early.
--_____ did Dave go on vacation? -- He went to the mountains.
—Thanks for your help,Mary! —________.
—_________ are these trousers? —The trousers on the bed? They are only $15.
—Who ______ P.E? —Sam _______.