1222
Carbon 's covalent radii are normally taken as 77.2 " pm ( C − C ) , 66.7 " pm ( C = C ) and 60.3 " pm ( C ≡ C ) , although these may vary depending on coordination number and what the carbon is bonded to .
 C, C, C
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 C, C, C