—______ do you write to your pen friend?—Once a week.A. How long B. How soon C. How often
We have been friends since________.
Li Hong has________the army for 2 years.
—Jenny,I need some milk. —OK,Mum.________do you need?
—How long have you________this book? —For one week.
Two fifths of the rice in our city________from Heilongjiang and Jilin.