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. RUSSIAN - FRENCH - ITALIAN
= 2. MICROSCOPE - PLAYGROUND - TROMBONE
= 3. DUCK SOUP - ANIMAL CRACKERS - HORSE FEATHERS
= 4. BREAD AND BUTTER - MIDGET GHERKIN - KOSHER DILL
= 5. SANTA ANA - SIROCCO - KHAMSIN
= 6. A SONG - A HEART - A POLICEMAN
= 7. PUMPKIN - POPPY - SESAME
= 8. FUJI - TREK - CANNONDALE
= 9. LOBSTER LAND - THE LUMBER STATE - THE BORDER STATE
= 10. FROSTY THE SNOWMAN - POPEYE THE SAILOR - GENERAL DOUGLAS MACARTHUR