The refraction of an object observed at the zenith is 0, while the refraction of an object observed near the horizon is about 34 arcmin.
(an object; observed; L:at the zenith) (The refraction of an object; is; 0) (an object; observed; L:near the horizon) (the refraction of an object; is; about 34 arcmin)
an object The refraction of an object an object the refraction of an object
observed is observed is
L:at the zenith
0
L:near the horizon
about 34 arcmin