Simplify the following text for a Grade 13 native English-speaking person.
Original: Its pattern of two-tier metropolitan and non-metropolitan county and district councils remains in use today in large parts of England , although the metropolitan county councils were abolished in 1986 , and both county and district councils were replaced with unitary authorities in many areas in the 1990s .
Simplified: Its pattern of two-tier councils remains in use today in large parts of England , although the metropolitan county councils were abolished in 1986 and it was replaced with unitary authorities in many areas in the 1990s .