Fill in the missing word or phrase.

Simulating Reality.
Sim City, the Sims are popular 1. ... games that simulate 2. ... . In Sim City players build cities that look like real 3. ... . There are houses and 4. ... in these cities.
We use computer simulatons 5. ... for fun. Some things are hard to be tested or 6. ... in real life as it's really 7. ... or difficult. Computer simulations make 8. ... possible. Pilots practise their 9. ... using flight simulators. Engineers can 10. ... and test new products before people start using them. They find 11. ... in cars and buildings and save 12. ... . With the help of computer simulators we can develop new thngs without 13. ... people's lives.