—Would you like to go out for a walk with us?—_________, but I must finish my homework first.
He has lost his pen. He is _______ it everywhere.
My mother told me _______ junk food at school.
There 's a teacher _____ with your parents in the teachers' office.
That computer_____ me quite a lot of money.
I never forget the days when I enjoyed ______ a good time in Beijing.