GRAMMAR CHECK
Why ____you ________ (leave) the city ten years ago?
Why did you leave the city ten years ago?
I ________ (wait) for two hours, but she ________ (not come) yet.
I have been waiting/have waited for two hours, but she hasn't come yet.
Mr. Green ________ (teach) English at this school since he ________ (graduate) from that university in 1986.
Mr. Green has taught English at this school since he graduated from that university in 1986.