Protesters formed 'a human chain' [=they stood next to each other with their arms linked] around the ancient tree to prevent it from being cut down.
In the United States, the President as the commander in chief is at the head of the military 'chain of command'.
I thought he really won the lottery but he was only 'pulling my chain'. [=he was only playing a joke on me]
(..) safe on the steep cliffs. The Ethiopian volcanoes are dormant, but elsewhere others still rage. Volcanoes form the backbone of the longest mountain chain on our planet - the Andes of South America. This vast range stretches miles from the Equator down to the Antarctic. (..)2006 TvShow: Planet Earth Title: Mountains Season: 1 Episode 2
(..) of the earth's surface where giant land masses are pulling away from one another. Lava rises to the surface through this crack in the crust creating a chain of young volcanoes. This one, Erta Ale, is today the longest continually erupting volcano on the planet, a lake of lava that has been (..)2006 TvShow: Planet Earth Title: Mountains Season: 1 Episode 2