97998
At Portland Bill , for example , which had a five-minute interval between fog-signals , this meant the horns had to be lowered , the two new charges inserted , and the horns raised again every five minutes during foggy periods .
 Portland Bill
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Portland Bill