Betty and Lingling are _____ the classroom. [ ]

Which module is the most difficult in this book?— I think _____ module.

__________ I have a ticket , please?—Sorry,sir. All the tickets were sold out ten minutes ago.

Would you like some coffee? — Yes, please. By the way, do you have any milk? I prefer coffee _____ milk. [ ]

I ________ to do chores, but I have to do them every day.