______ that the way people spend their holidays has changed a great deal in the past ten years.

Thank you for your help, Linda. You made ________ possible for us to finish the work in time.

Is Tom still in New York or already back at home?—I’m not sure _________. I’ll call to make sure.

I _____ the sea. I don’t know how to swim. [ ]

Most students like dinosaurs, but ______ of them know the story of dinosaurs.