Словообразование упражнение №13

Read the texts below and decide what part of speech in A, B, C or D best fits each gap in the sentences.
A (1) _______ lighthouse is a structure from which light is projected at night, or which serves as a marker by day, (2) _______ ships (3) _______ in coastal waters. Lighthouses are constructed at important points on a coastline, at (4) _______ to harbours and estuaries, on rocky ledges or reefs, on islands, and even in the water. Lighthouses help (5) _______ a ship's location, warn ships of (6) _______ hazards, and (7) _______ them that land is (8) _______ .
Lighthouses differ from smaller beacons in that a lighthouse includes (9) _______ quarters for a lighthouse keeper. Today, however, most lighthouses use automatic electric lights that do not (10) _______ a full-time resident operator.

1. commonly common commonness commoner	2. guided to guide guidance guideline	3. sailer sailor sails sailing	4. enter entrant entrances entered	5. identify identifying identification identified
6. potentially potential potency potent	7. notifying notification notify notified	8. nearer nearly nearness near	9. living live alive life	10. requirement require required requiring