Key information, Contextual meaning and plural forms

What is the meaning of "owe" in the following sentence?

We owe many of our modern ideas about fairies to Shakespeare and stories from the 18th and 19th centuries.

The origin of fairies is a memory of real people, not spirits.

What is the plural form of "memory"?
*Answer must be in small letters

What is the key information of the following sentence?

While most people no longer believe in fairies, only a hundred years ago some people still thinks they might exist.

Some photography experts thought that the photos of fairies were fake, while others weren't sure.

The meaning of "expert" is

• a person who doesn't believe in fairies

• a person who studies about the nature of fairies

• a person who is very knowledgeable about in a particular area

Fairies today are the stuff of children's stories, little magical people with wings

What is the singular form of "fairies"?

*Answer must be in small letters