The iron filings were used to represent where the magnetic field is.
(The iron filings; were used; to represent where the magnetic field is) (The iron filings; to represent; where the magnetic field is) Context(The iron filings to represent,List([0, 39))):(the magnetic field; is; )
The iron filings to represent,List([0, 39))
The iron filings The iron filings the magnetic field
were used to represent is
to represent where the magnetic field is
where the magnetic field is