16303
The accumulation of metal ( Co , Cr , Cu , Mn and Zn ) in freshwater Ulva ( Chlorophyta ) and its habitat .
 Co, Cr, Cu, Mn, Zn
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Co, Cr, Cu, Mn, Zn