Answer:
not discovered or known about; uncertain.
keep from being seen; conceal.
Explanation:
They don't write stories.
He was singing a song.
Answer:
D. sound
Explanation:
When the string is plucked, a certain amount of the potential energy is converted to kinetic energy.
I don't have the passage, but one could be appearance. Another could be something about jobs... e.g. Some people think women shouldn't be in the military, or be mechanics, or that men shouldn't be hair stylists or models
