dirty air in towns and cities
pollution
big numbers of people in one place
crowds
things some people don’t want and leave on the street
rubbbish / garbage
buses, undergrounds and trains that people pay to travel on
public transport
the busiest period in a city for traffic
rush hour
a long line of vehicles waiting to move
traffic jam
when an electrical system stops working
power cut
words or pictures that we see on walls
graffiti
areas of grass in a city
green spaces
