{HEAD ~ An electric field} accelerates ions and {TAIL ~ electrons} in directions parallel to the electric field 
accelerates
{ HEAD ~ An electric field } accelerates ions and { TAIL ~ electrons } in directions parallel to the electric field
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH