7090
This work demonstrates that substitution of lithium by sodium may offer an unexpected route towards rechargeable metal - air batteries .
 Chemical: lithium; Chemical: sodium
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: lithium, sodium 
Answer:
 Chemical: lithium; Chemical: sodium