Listening to peaceful music.  as well as taking exercise,___________ a lot in relieving people 's sad emotions.

While a huge amount of money ___been spent stopping pollution , large quantities of water_    _still heavily polluted．

They usually have lunch at school, ________?

Not only John and Tom but also their sister, Mary, _______ great interest in the piano lessons.

．The young often＿＿＿the old in our town．