If all the inventions we invented didn’t t exist which invention would you invent first ?

Question: If all the inventions we invented didn't t exist which invention would you invent first ?
- Keywords:
  history,
  invention
Asked by Mathew L-T to Hilly, Lee, Liz, Tadhg, Yasmin on 14 Jun 2015.
- Lee Margetts answered on 14 Jun 2015:
  
  Hi @Mathew L-T. Its not really an invention, more of a discovery, but I think fire is really important. Our control of fire and its use in making tools has played an important role in all the inventions we have today.
- Yasmin Ali answered on 14 Jun 2015:
  
  Glasses or contact lenses. My sight is pretty terrible, I would definitely be dead by now if I lived in times before eye correction existed.

Question: If all the inventions we invented didn't t exist which invention would you invent first ?