Answer:
My days are numbered. What am I?
I have no voice but I can teach you all there is to know. I have spines and hinges but I am not a door. Once I’ve told you all I cannot tell you more.
First you see me in the grass dressed in yellow gay; next I am in dainty white, then I fly away. What am I?
I sleep by day, I fly by night. I have no feathers to aid my flight. What am I?
The person who makes me doesn't need me. The person who buys me doesn't use me. The person who uses me doesn't know it. What am I?
I am your mother's brother's only brother in law. Who am I?