If we cut down more trees, the forests (a)   (disappear).

There (a)   (be) more deserts if the forests will disappear.

If there (a)   (be) more deserts, the planet will become hotter.

Many plants and animals will die if the planet (a)   (become) hotter.

‘If we (a)   (not do) something soon, electronic products will create serious problems for the environment.

We use more and more energy because we buy more and more electronic gadgets. If this situation (a)   (continue), each house will need an incredible quantity of energy.

Nowadays, some people think that they (a)   (not be) able to brush their teeth if they don't have an electric toothbrush.

If we forget to switch off all these electronic gadgets, we (a)   (use) up all of our electricity for nothing.’

The school will save money if they (a)   (produce) extra electricity.