Sunday brain training!

5년 전

Get yourself a hot cup of coffee, relax somewhere comfortable, and see if you can figure out this challenge!
One of the four words does not belong with the other three. Which word does not belong? What is it that the others have in common? 


1. Green, yellow, red, blue. 
2. April, December, November, June.  
3. Carrots, radishes, potatoes, cabbages. 
4. Fork, comb, rake, shovel.