large groups of people who are together in one place
crowds
damage caused to water, air, etc. by harmful substances or waste
pollution
a line of cars, trucks, etc. that are moving slowly or not moving at all
traffic jam
the time when a lot of people are travelling to or from work and so roads and trains are very busy
rush hour
when the supply of electricity suddenly stops
power cut
areas of grass, trees or other plants in a town or city
green spaces
a system of vehicles such as buses and trains which operate at regular times and that the public use
public transport
things that you throw away because you do not want them
rubbish
writing or pictures painted on walls and public places, usually illegally
graffiti