Which is the best revision to make sentence 3 shorter without changing its meaning?
before scientists came up with the technology to harness coal and oil, solar energy was
one source of energy
solar energy was one of a few sources of energy before scientists came up with
technology to harness coal and oil power
scientists came up with technology to harness coal and oil, and solar energy was only
one source of energy.
before scientists harnessed the power of fossil fuels, solar energy was one of the few
sources of energy.

You make a sentence shorter without changing its meaning by, switching words around and also adding different words (synonyms) to the sentence making it not change it's meaning.

Explanation:

The explanation to this is it gives you greater knowledge about the subjects and also gives a a greater idea of how to paraphrase this and gives you practice for next time you do it! Good luck on your answer to your question! I hope this helps out!

mine is hell,we all hate each other,we fight but me and my mom,dad,and siblings get along.