Fill in the blank with the correct form of words in the bracket

IV. Fill in the blank with the correct form of words in the bracket.
26. You can't do that, man - use your ______ ! (intelligent) 
27. We use that equipment for ____ purposes.(education) 
28. Pele is a ____ hero in Brazil. (nation)
29. New York is an ____ city with many skyscraper. (excite)
30. My future house will have ____ energy. (sun)