With no explanation, label text_A→text_B with either "strengthener" or "weakener".
text_A: Spectators look on in amazement as a basketball player dunks the ball. During the Slam Dunk Contest, people watch in amazement as a player dunks, shattering the backboard.
text_B: The player comes down and moves out of the way of the flying glass from the backboard.
strengthener.