范文：

　　The professor talks about establishing shot in the lecture which is a shot used to provide context for the rest of the scene. And he uses a new movie as an example. In one scene, before the action and talking started, an image of a city is shown to the audience to provide context. Things in the city looked old fashioned, and the city itself was gloomy and dark. And it was raining too, and kind of foggy, all these elements worked together to create a mysterious feeling. So when the action started, the audience would get the idea that the story of the movie takes place in a big city during the 1940s, and the rest of the movie will be very mysterious and dark.