Complex sentence: TENYAS was formed on 1 April 1999 as a merger of the former Cleveland, Humberside and North Yorkshire ambulance services and served the urban areas of Middlesbrough, York and Hull along with the rural areas of the Yorkshire Dales, Wolds, covering an area of approximately.
Split into simpler sentences: TENYAS was formed on 1 April 1999 as a merger of the former Cleveland, Humberside and North Yorkshire ambulance services. TENYAS served the urban areas of Middlesbrough, York and Hull, and the rural areas of the Yorkshire Dales, Wolds, covering an area of approximately.