The seasons keep changing because the tilt of the Earth's axis never changes while the Earth circles the Sun.
(The seasons; keep changing; because the tilt of the Earth's axis never changes) (the tilt of the Earth's axis; never changes; T:while the Earth circles the Sun) (the Earth; circles; the Sun)
The seasons the tilt of the Earth's axis the Earth
keep changing never changes circles
because the tilt of the Earth's axis never changes
T:while the Earth circles the Sun
the Sun