Simplify the following text for a Grade 9 native English-speaking person.
Original: In 2005 Dan Lewis , author of The Essential Guide to Quangos , for example , claimed that the UK had 529 quangos , many of which were useless and duplicated the work of others .
Simplified: In 2005 Dan Lewis , author of The Essential Guide to Quangos , claimed that many quangos were useless and duplicated the work of others .