1. She has already visited all 196 countries in the world / She is the youngest person to travel to every country in the world. (any 1)
2. so that travellers can decide the cheaper mode of transport to take / to avoid being cheated by taxi drivers (any 1)
4. It’s so user-friendly that even someone who’s never looked at it before would be able to navigate the site.
5. flights that emit less carbon dioxide
6. (i) NG
7. (i) burned out