He was the first to convert mechanical energy into electric energy, the crucial step towards development of the electric motor and generator.
(He; was; the first to convert mechanical energy into electric energy, the crucial step towards development of the electric motor and generator) (the first; to convert; mechanical energy; into electric energy, the crucial step towards development of the electric motor and generator)
He the first
was to convert
the first to convert mechanical energy into electric energy, the crucial step towards development of the electric motor and generator
mechanical energy into electric energy, the crucial step towards development of the electric motor and generator