540
All of a sudden , a brand-new Grey BUS appears in the top of the screen at a speed of 50 kilometers an hour
 Grey, BUS, top, 50 kilometers an hour
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: vehicle type, position of vehicle, color of vehicle, orientation of vehicle, vehicle velocity, vehicle range, brand of vehicle, vehicle model, SUV, hatchback, sports car, sedan, bus, truck, vintage car, coupe, roadster, estate car, motorcycle, MPV, van 
Text: {0} 
Answer:
 Grey, BUS, top, 50 kilometers an hour