With no explanation, label text_A→text_B with either "strengthener" or "weakener".
text_A: A blurred person on a motorized bicycle while three people are on the right side of the street. Three older people wait on the curb as traffic whizzes past them.
text_B: The teenager impresses his three friends with the lawnmower motor that he attached to his bicycle to keep up with traffic.
weakener.