The parking lot was ___ many tour buses, taxis and bicycles.
If_____litters, our world will be more beautiful.
—Can the plane fly _____ the Atlantic Ocean? —Yes,but it needs to go_____the clouds for hours.
—Can you tell me _____when the teacher came into the classroom? —Sorry,I don’t know.
The teacher said that _____ of the boys would take part in the fashion show.
—______ did your sister leave China? —She______ for three years .