1. Petrol-powered cars are not eco-friendly, so they won't||will be popular.
2. We will||won't travel by teleporter soon because it is faster.
3. Rich people will||won't choose to travel to other planets for their holidays.
4. People won't||will take holidays in crowded places as in the past.
5. Bullet trains will||won't soon become a popular means of transport in Viet Nam because they are green and safe.
