1. What is the primary source
of energy for living beings on
earth?

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
The sun, center our planetary system
star of the way galaxy (our
), is the source the energy that
processed and consumed living
beings. Intense reactions in the
liberate light and energetic
radiations into surrounding space.
Some this energy reaches planet.