—How many students are there in your school?—_______ students, I think. A. Thousand of B. Three thousands C. Three thousand
—Thank you, Thomas. —________.
— Is this a key? — ________ .
—Is this your baseball, David? —No, it's not . It's Helen's.
— ________is your notebook? —It’s green.
Look atthe map. It’s a map ________ China.