teacher apart

0He was a round little man with a red face and a whole box of tools with dials and wires. He smiled at Margie and gave her an apple, then took the 01b00teacher apart02b00. Margie had hoped he wouldn't know how to put it together again, but he knew how all right, and, after an hour or so, there it was again, large and black and ugly, with a big screen on which all the lessons were shown and the questions were asked. That wasn't so bad. The part Margie hated most was the slot where she had to put homework and test papers. She always had to write them out in a01b00 punch cod02b00e they made her learn when she was six years old, and the mechanical teacher calculated the mark in no time. 02br
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00Please explain the bold group of words.0-