Before directional instruments were invented, sailors navigated the seas by fixing their compass on the North star;
(directional instruments; were invented; ) (sailors; navigated; the seas; T:Before directional instruments were invented) Context(sailors navigated,List([46, 63))):(sailors; navigated the seas by fixing; their compass)
sailors navigated,List([46, 63))
directional instruments sailors sailors
were invented navigated navigated the seas by fixing
the seas T:Before directional instruments were invented
their compass