根据句意，用括号中所给词的适当形式填空。（每小题1分，共5分）
Mike goes to see his grandparents _________ (one) a week.
Exercise is  ______  (health) for the mind and the body.
This flower is _____ (good) than that one.
Which city is ____________ (beautiful),Beijing,Shanghai or Hangzhou?
We ____________ (not have) enough money to buy food last night.