8521
WAAS uses a network of ground-based reference stations , in North America and Hawaii , to measure small variations in the GPS satellites ' signals in the western hemisphere .
 location: North America; location: Hawaii
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: North America, Hawaii 
Answer:
 location: North America; location: Hawaii