Theory:

Margie was scornful. “School?  What’s there to write about school? I hate school.”
     Margie always hated school, but now she hated it more than ever. The mechanical teacher had been giving her test after test in geography, and she had been doing worse and worse until her mother had shaken her head sorrowfully and sent for the County Inspector.
Explanation:
 
Margie disliked the word ‘school. She said that what was there to write about it and an entire book had been written about school.
Margie’s school is a machine. (which teaches you and not that school where we all go).
Margie’s school was a virtual classroom. It was not a real school like we have today. So, in the future, we think that the schools will be virtual classrooms. There will be machines that will be teaching the children. Margie did not like this machine because it was giving her many tests in geography, which was quite difficult for her, and she was doing very bad. Finally, her mother thought that there was something wrong with the machine so, she had called the County Inspector to check it. (A county inspector is maybe a person of that period who checks and repairs the mechanical teachers that the children of that time have.)
 
Meanings of difficult words:
 
Numbers
Word
Meaning
1.
ScornfulContemptuous; showing you think something is worthless, show your dislike for something.
Reference:
National Council of Educational Research and Training (2006). Beehive. The fun they had - Isaac Asimov (pp. 05-09). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.