How dirty the windows are! They reallyrequire _______.

Have you ever _______ to bring yourhomework to school—Yes. I _______ it at home once last term.

The September 11 attack has been _____ by the entire international community.

Professor Jordan gave us _______ lecture this afternoon and most of us were confused.

The ticket ______ him ￥20.And flying to the USA ________him two days.