Explain why the history of Egypt remained a mystery for centuries?

Egyptian civilization developed along the Nile River in large part because the river's annual flooding ensured reliable, rich soil for growing crops. ... Ancient Egyptians developed wide-reaching trade networks along the Nile, in the Red Sea, and in the Near East.

a factory opens that mass-produces light bulbs.

explanation:

not sure if that's an answer to your questions but this is an example! : )

since learning about his learning patterns, logan has become very aware of the thoughts and feelings he experiences as he listens to the “internal chatter” of his patterns.