22531
Reflecting the varied electrification schemes on the Northeast Corridor the Amtrak units could operate at three different voltages : 11 kV 25 Hz AC , 12.5 kV 60 Hz AC , and 25 kV 60 Hz .
 location: Northeast Corridor; organization: Amtrak
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: Northeast Corridor, Amtrak 
Answer:
 location: Northeast Corridor; organization: Amtrak