40696
British warships , constructed using such innovations as steam power combined with sail and the use of iron in shipbuilding , wreaked havoc on coastal towns ; such ships ( like the " Nemesis " ) were not only virtually indestructible using contemporary available weapons , but also highly mobile and able to support a gun platform with very heavy guns .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
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