Please choose the correct ending to complete the given sentence: Fixing bicycle: A person sitting next to a bike demonstrates how to remove and replace a bike chain using a small tool. the video

Ending1: ends with the closing graphics and credits shown on the screen. Ending2: cut to clips of several bikers at a competition which include several injured and schools only a few blocks away and several bikes at their construction sites. Ending3: shows a closeup of the machine as well as the tools tiny tack on the back of the bike, as well as some cameras on front it. Ending4: shows several clips of actions they took on the bike to install in the seat of a bike.

Answer format: ending1/ending2/ending3/ending4