Now that the sign reads, “No person ______ smoke here”, please choose a seat in the smoking area over there if you _______ smoke.

 Everyone ______ be polite to the old people.

It has been announced that students _______ remain in their seats until all the papers have been collected.

－Are people around you used to _______things online?－Yes. It’s much easier, and also cheaper.

 -Look at the picture on the wall. It         be David's.-Yes, his name is on the first page.