Carbon dioxide is a big ........... to pollution.

If we are sensible in how we use the resources they will (8) ........ indefinitely.

We need food, water, air, energy, medicines, warmth, shelter and minerals to keep us fed, comfortable, healthy and (7) ……...

As a (5) ........ the planet's ability to support people is being reduced at the very time when rising human numbers and consumption are (6) ........ increasingly heavy demands on it.

As a (5) ........ the planet's ability to support people

Everywhere fertile soil is (4) ........ built on or washed into the sea.

The western world (2) ........ on consuming two-thirds of the world's resources while half of the world's population do so (3) ........ to stay alive.

The western world (2) ........ on consuming two-thirds of the world's resources while half of the world's population do