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one caravan trail developed into the silk road . during the height of caravan travel , which lasted until the 19th century , a single caravan of muslim pilgrims journeying from cairo and damascus to mecca might employ as many as 10,000 camels .
 caravan, pilgrims
Please list all entity pairs containing a certain relationship in the given options.Output format is "word1, word2; word3, word4". 
Option: component whole, NA, instrument agency, member collection, cause effect, entity destination, content container, message topic, product producer, entity origin 
Text: {0} 
Answer:
 caravan, pilgrims