It is a thick, black substance called petroleum.

 ________ is energy that comes from moving water.

____ is formed as the Sun heats Earth unevenly.

What is the act of saving, protecting, or using resource wisely?

To _______ means to use something more than once.

Burning ________ transforms the stored energy into thermal energy, gas, or fuel.

Windmills called _________ change wind's kinetic energy into electric energy.

  What is the black, powdery substance that released in an Industrial plants known as steel mills?

It is any harmful substance that affects Earth’s land, air, or water.

It can cause breathing problems and eye irritation.

It is the most plentiful fossil fuel, that is found between rock layers.

What do we call the scientist who monitors the supply of uranium and predict how much electricity is produced?

 Some of the electricity we use comes from __________.

 ____________ can provide energy for cooking and heating our homes.

A larger portion of the energy humans use comes from __________.

To _________ means to lessen the amount of something is used.

The wind is formed as warm air_____ and cooler air sink.