Word forms for theory

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!

   theoretical      Theoretically      theories      theorizes      theory   

  1. Current [] trace our first human ancestor to Africa about 5 to 7 million years ago.
  2. We will be examining three [] perspectives on the question during the next few days.
  3. Einstein's famous [] that E = mc2 has been shown to be true by modern physics.
  4. The notion of the Big Bang [] that the universe began as a huge explosion of matter.
  5. [] speaking, the planet Mars appears to have had most of the conditions necessary to support simple life forms at least at some point in time, but no evidence of life past or present has yet been found on the planet.