Please choose the correct ending to complete the given sentence: Welding: Joe morin from titan alloy is talking about welding aluminum. He is doing a tutorial on how to fix aluminum. he

Ending1: is also working on improving aluminum which shows its solvable by working outdoors on a roofed roof. Ending2: is also talking about how to remove abrasive metal from the bottom of a flame resistance welding machine, such as the pivoting stilts. Ending3: shows a new product called nova, which is an electrode for cleaning dirty aluminum. Ending4: is talking about special effect welding the metal.

Answer format: ending1/ending2/ending3/ending4