Complex sentence: It was first shown on Christmas Day 1989 on ITV in the UK, during the premieres of Nick Park's Wallace and Gromit and the Paddington Bear episode, "The Ghost of Christmas Paddington".
Split into simpler sentences: It was first shown on Christmas Day 1989 on ITV in the UK. It also aired during the premieres of Nick Park's Wallace and Gromit and the Paddington Bear episode, "The Ghost of Christmas Paddington".