I think it’s necessary for us English well.
----______________your classroom clean? ---Yes. We ____________ it after school every day.
- _______is it today? -It's _______the 21st of June.
--- _______is great fun. It can make us happy.
—The girl __________ glasses is my sister. Do you know her? —No, I don’t.
Would you like ________ me how ________ after my bird?