The first two-wheeled rider-propelled machine C ______ by Baron Karl von Drais de Sauerbrun of Germany. In 1817 he rode it for 14 km. (INVENT)

1. The word 'INVENT' in parentheses indicates that the word should be derived from 'invent'.
2. The sentence is in the past tense and describes an invention.
3. The correct past participle form for a passive construction is 'invented'.