Complex sentence: The first section of the motorway, and the first motorway in the country, the Preston by-pass, was built by Tarmac Construction and opened by the then Prime Minister Harold Macmillan on 5 December 1958.
Split into simpler sentences: The first section of the motorway and the first motorway in the country was the Preston by-pass. It was built by Tarmac Construction and opened by the Prime Minister Harold Macmillan on 5 December 1958.