There is _______ “u” and _______ “f” in the word “unfamiliar”.
Teenagers _______ allowed to drive in the street .
I don't know _______.Can you tell me________?
That's very kind ______ you. I know it's very hard _______ you to do that.
David used to _____________ in the afternoon.
How do you study _______a test? I study _______working with friends.