5.When a spaceship circulates around a planet without using its power, why do the astronauts in it float?
(A) Because there is no gravity in space.
(B) Because there is air inside the spaceship.
(C) Because the spaceship and the astronauts are free falling together.
(D) Because the spaceship is too far from any massive body.
(E) Because the spaceship can shield the astronauts from gravity.

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