the winter grew very very cold : the duckling was obliged to swim about on the water to keep it from freezing quite over , but every night the hole he swam in became smaller and smaller . it froze so hard that the ice cracked again ; the duckling had always to be moving about to keep the water open , till at last he was tired out and sat still , and was frozen fast in the ice .
he swam to keep it from freezing quite over .
why was the duckling obliged to swim about on the water ?
why was the duckling obliged to swim about on the water ?