Make sure the gas is turned off after a bath, which would ________ cause danger.

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

Though she did not know Boston well, she made her way_____to the Home Circle Building.

Bob is ________crazy about Beethoven that he knows all his works well.

--- You should have gone to see the film. It’s very moving. ---______, we arrived too late to catch the last bus.