The words in each set have a common connection, something that bonds all three of them in some way, perhaps shared features or maybe it's characteristics...and then again it could be a manifestation of common attributes.
Can you find a Commonality?
= 1. ITALIAN - RUSSIAN - FRENCH
= 2. TROMBONE - MICROSCOPE - PLAYGROUND
= 3. HORSE FEATHERS - DUCK SOUP - ANIMAL CRACKERS
= 4. KOSHER DILL - BREAD AND BUTTER - MIDGET GHERKIN
= 5. KHAMSIN - ANTA ANA - SIROCCO
= 6. A POLICEMAN - A SONG - A HEART
= 7. SESAME - PUMPKIN - POPPY
= 8. CANNONDALE - FUJI - TREK
9. THE BORDER STATE - LOBSTER LAND - THE LUMBER STATE
= 10. GENERAL DOUGLAS MACARTHUR - FROSTY THE SNOWMAN - POPEYE THE SAILOR