With no explanation, label text_A→text_B with either "strengthener" or "weakener".
text_A: A rock climber dressed in yellow and wearing a red safety helmet is scaling the smooth wall of a high cliff, while another member looks on from the boat in the water. A rock climber dressed in bright yellow and wearing a red safety helmet is scaling the smooth wall of a high cliff
text_B: They're difficult to see.
weakener.