1. What is the primary energy
source for life 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 primary energy source life on
earth is sun. The sun plays
important role of keeping planet
warmed and it source of the
luminous used in
photosynthesis.This energy
converted into organic material the
photosynthetic autotrophic beings
consumed by the other beings.