Answer:
It means that you don't or won't believe something until you actually see it in real life.
Every Gerund ends with - ing , so in this sentence we have ‘marooning’. Ths is a verb that acts as a noun.
Answer:
improving air quality :
1. keep it clean. a clean house may be a healthier house , because good indoor hygiene can greatly cut down on dust and animal dander
2. keep the greenery outdoors
3. change your filters
4. invest in an air purifier
5. let fresh air in
So that the rock can still be moved and they can escape
Hope I helped!! :)