Please choose the correct ending to complete the given sentence: Assembling bicycle: A green bike is leaned against a group of boxes. a man

Ending1: is sitting on the bike in front of a stack of boxes. Ending2: is welding something metal on a table. Ending3: removes the front tire of the bike. Ending4: is screwing on a safety bar.

Answer format: ending1/ending2/ending3/ending4