The words in each set have a common connection, something that bonds all three of them in some way, shared features or characteristics...a manifestation of common attributes.
Can you find a Commonality?
= 1. ATHOS - PORTHOS - ARAMIS
= 2. JOHN L. SULLIVAN - JACK JOHNSON - JACK DEMPSEY
= 3. MARY, QUEEN OF SCOTS - MARIE ANTOINETTE - LADY JANE GREY
= 4. CANDIDATES - TRACK STARS - PANTYHOSE
= 5. SNOW - GUM - MOTH
= 6. FLORIDA - THELMA - J.J.
= 7. EARTH STARS - PUFF BALLS - TOADSTOOLS
= 8. A PERSON - AN ARTICHOKE - A DECK OF CARDS
= 9. ODD - IRRATIONAL - EVEN
= 10. WEB - HEAD:WALL - CRAWLER:SPIDEY