Because of the ... from factories, cars and other human activities the ozone layer becomes thin.
pollution
A lot of wild animals are in ..., we ought to protect them from dying out, for example, create national parks.
danger
... happen when the water level rises quickly.
floods
Rising temperatures cause melting of ...
icebergs
People often start forest ... when they aren't careful. As a result, a lot of trees and animals die.
forest fires
When you ... , you help the planet to get cleaner.
recycle
Millions of .... bottles end up in the ocean and harm marine life.
plastic
... produce toxic substances that posion water and soil.
landfills
When it doesn't rain for a long time, there is a ... It can lead to hunger in some countries.
drought
We shouldn't ... water. Close the tap!
waste
