33.It was not until one night_____we were doing our cleaning-up I got curious and wanted to see what was on the top floor.
______ it is to learn English on the internet!
Would you____holding this box for me while I open the door?
Most of us know we should cut down fat, but knowing such things isn’t much help when it____shopping and eating. A refers to B. speaks of C. focuses on D. comes to
He didn't realize he had forgot his bag _____ the plane had taken off.
_____ of the new aircraft will start next year.