A) rare to find and hard to form because in the passage, it mentions that you need specific conditions but they are hard to find (because they get destroyed before they are discovered)
Verb because it uses words like, will be, call,create
The window had 5 panes of glass.
Happy studying ^-^
Yes.
An abstract noun is a noun which denotes a quality, idea, or state of being and not a physical object.
This means that "knowledge" is an abstract noun.
