4804
The reversible cycling of CaO adsorbents to CaCO ( 3 ) for high - temperature CO ( 2 ) capture is substantially improved by mechanical treatment .
 CaO, CaCO ( 3 ), CO ( 2 )
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 CaO, CaCO ( 3 ), CO ( 2 )