Complex sentence: The British prime minister Margaret Thatcher worked at J. Lyons & Co for a brief period in the late 1940s as a research chemist at their laboratories in Hammersmith, London.
Split into simpler sentences: The British prime minister Margaret Thatcher worked at J. Lyons & Co for a relatively brief period in the late 1940s. However, her capacity at J. Lyons was to work as a research chemist at their laboratories in Hammersmith, London.