1 If scientists invent cars that run without petrol, __________.
2 If time travel becomes possible, __________.
3 If there are 10 billion people on earth, __________.
4 If computers can speak all languages, __________.
5 If people can fly to Mars in 24 hours, ___________.

1 If scientists invent cars that run without petrol, pollution levels will decrease significantly.
2 If time travel becomes possible, we might be able to visit the past and the future.
3 If there are 10 billion people on Earth, resources like food and water could become scarce.
4 If computers can speak all languages, communication between countries will become much easier.
5 If people can fly to Mars in 24 hours, space tourism will become a reality.