– Excuse me. Where is the bus stop, please?–I’m sorry. I don’t know the way, _______.
This is the most beautiful park I have _____ visited.
Xi’an is a city with many places of interest and __ tourists come here every year.
—_____ you _____ your homework yet? —Yes, I _____ it ten minutes ago.
It’s necessary for you _____ exercise every day.
—I _______ here since I was five years old.