—Must we keep the window _______ all the time? —No, you don’t have to. 

I went to the beach. Where did you go           the school trip?

— What other rules do you have in your class?— Each student has to 　　　　 a composition once a week.

—Susan, do you like my skirt?—Yes, it is very _____. How much does it ______?

-- Will you buy this nice camera, Henry?-- No. It’s too expensive. I can’t ________ it.