For each group, find a word that can be added to each member to make another word or phrase. For example, given DRAW, HOLD, IN, FORTH, the word WITH can be combined with each of them to make a new word or phrase.
Answer all of the groups that have word clues first. Once all of the clues are answered for an unknown set, 1-2-3-4 for example, then the related clue (5) can be answered. Follow this logic throughout the puzzle. The last clue to be answered will be # 21
-1. cap, light, pump, nerve
-2. front, head, feed, air
-3. farm, home, mark, slide
-4. tape, sun, hand, chair
-5. (gas-line-land-deck)
-6. size, wing, camera, door
-7. stock, jack, shot, crack
-8. stick, under, head, stripe
-9. escape, latch, low, stone
-10. (man-pot-pin-key)
-11. roll, sea, cover, post
-12. screw, black, hard, coat
-13. car, side, room, football
-14. year, pen, tail, house
-15. (bed-top-pool-;ight)
-16. ink, sand, crop, cold
-17. place, law, cold, room
-18. fire, kick, double, stage
-19. girl, slip, charge, bed
-20. (stone-common-back-cover)
-21. (main-hole-table-ground)