Please choose the correct ending to complete the given sentence: Doing karate: . two boys in blue karate suits and red belts

Ending1: are doing style to one another in a homemade karate mincing thing. Ending2: are standing on a stage in a school cafeteria and they are doing a karate routine in unison. Ending3: start to split into two groups to cover the left side of the mat. Ending4: and black shirts are working by lifting up hualists and throwing them to the sides of a mat or a mat a place.

Answer format: ending1/ending2/ending3/ending4