Our headmaster isn’t in his office. I can’t find him anywhere. Did you notice him ______ the office?
Now most families have only one child _____ our country’s one-child policy.
—Can you write the number eighty-five thousand, six hundred and twenty-six? —Yes, it is _____.
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.