______ are the Olympic Games held?—Every three years. [ ]

You don’t want to visit any other mountain if you have seen wu yue, but you won’t wish to see even wu yue_____________ returning from Mount Huangshan.[ ]

The summer vacation is coming. Could I ask you _____ your plan for vacation.[ ]

He has never been to Shanghai, _____? —_______. He has been there twice.

_________ should not be allowed to go out at night.