the precessional effect of gravity between the two is an effect at 90 degrees to the Sun pull, which makes the Earth both spin and orbit around the Sun.
(the precessional effect of gravity between the two; is; an effect at 90 degrees to the Sun pull) (the Sun pull; makes; the Earth)
the precessional effect of gravity between the two the Sun pull
is makes
an effect at 90 degrees to the Sun pull
the Earth