ENVIRONMENT

3. FUELS WHICH ARE THE REMAINS OF PLANTS AND ANIMALS
4. THE HEATING UP OF THE EARTH'S ATMOSPHERE BY POLLUTION
6. ANIMALS OR PLANTS IN DANGER OF BECOMING EXTINCT OR DISAPPEARING IN THE NEAR FUTURE
10. BOXES, CARTONS AND CANS WHICH CAN EASILY BE DECOMPOSED BY ORGANISMS SUCH AS BACTERIA, OR BY SUNLIGHT, SEA, WATER, ETC.
12. GASES AND OTHER SUBSTANCES
13. PROCESS WASTE MATERIAL SO THAT IT CAN BE USED AGAIN

1. THE BURNING OF SOME FUELS CREATES CARBON DIOXIDE, CARBON MONOXIDE, SULPHUR DIOXIDE, METHANE AND OTHER GASES WHICH RISE INTO THE ATMOSPHERE
2. FUEL WHICH HAS BEEN MADE WITHOUT LEAD ADDITIVES
5. POLLUTED PRECIPITATION WHICH KILLS TREES
7. AREA OF FARMING LAND OR WOODS AND PARKS WHICH SURROUNDS A TOWN
8. LIVING THINGS, BOTH LARGE AND SMALL, IN MANY PARTS OF THE WORLD
9. THICK WOODED LAND IN TROPICAL REGIONS WHERE THE PRECIPITATION IS VERY HIGH
11. GRADUAL WEARING AWAY