What does it mean for a process to be sustainable?

• It is very expensive.

• It uses a lot of resources quickly.

• It can continue without harming the environment.

• It can be done without stopping.

Which of these is a sustainable way to make power?

• Burning wood

• Burning coal

• Using wind

• Using oil

Why is coal not a sustainable resource?

• It is too clean.

• It will run out one day.

• It is too easy to find.

• It is too cheap.

What happens when we use up all the coal?

• It will become cheaper.

• It will last forever.

• We can make more.

• We will have none left.

Which of these is NOT a sustainable power source?

• Coal energy

• Solar energy

• Wind energy

• Wave energy