Polar bears live on sea ice, which they use as a platform for hunting seals.
__________for the bus, I heard a noise,
To the parents’ worry, some middle school students are ______ computer games and completely forget their studies.
It was in 1969 ______ two Americans went to the moon by spaceship.
She pretended to be calm but _______she was more than nervousat the time she was being questioned.
The problem ________ at the meeting yesterday.