We add an extra day every four years to the usual 365, to account for the approximate 365.25 days it takes for Earth to orbit the sun.
(the approximate 365.25 days; takes; it) (Earth; to orbit; the sun) (We; add; an extra day; T:every four years; to the usual 365) Context(We add,List([0, 6))):(We; add an extra day to account; for the approximate 365.25 days)
We add,List([0, 6))
the approximate 365.25 days Earth We We
takes to orbit add add an extra day to account
it
the sun
an extra day T:every four years to the usual 365
for the approximate 365.25 days