Polar bears live      on sea ice，which they use as a platform for hunting seals

Plants need water and sunlight to grow well. _____, a healthy body requires a balanced diet. 

 I won’t buy the house, which was too expensive and too big. ______, I’d grown fond of our little rented house.

．Jack’s room always has the awful smell of an apartment whose windows are________opened.

Many people say______ is shown on television.