5934
A facile and low - cost approach has been developed to fabricate porous CuO nanobelts directly grown on a Cu substrate .
 Chemical: CuO; Chemical: Cu
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: CuO; Chemical: Cu