8566
Observation of direct vibrational excitation in gas - surface collisions of CO with Au ( 111 ) : a new model system for surface dynamics .
 Chemical: CO; Chemical: Au
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: CO, Au 
Answer:
 Chemical: CO; Chemical: Au