Please choose the correct ending to complete the given sentence: Fixing bicycle: A man speaks to camera in front of bicycles. The man places a part on a bicycle being worked on. the man

Ending1: tightens the part on the bicycle. Ending2: uses tools involved to unscrew and remove the parts of the bike. Ending3: demonstrates how to work every part. Ending4: continues speaking in front of a treadmill.

Answer format: ending1/ending2/ending3/ending4