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This great wall of trees acts as a vital " safety valve , " regulating the flow of water into the Shihmen Reservoir , the Tanshui River and the Lanyang River , on which millions of people in northern Taiwan depend for the water they drink .
 location: the Shihmen Reservoir; location: the Tanshui River; location: the Lanyang River; geographical social political: Taiwan
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: date, organization, person, geographical social political, national religious political, facility, cardinal, location, work of art, law, event, product, ordinal, percent, time, quantity, money, language 
Text: {0} 
Answer:
 location: the Shihmen Reservoir; location: the Tanshui River; location: the Lanyang River; geographical social political: Taiwan