Given the task definition and input, reply with output. Indicate a text span in the passage about which an inquisitive question is asked. (note, don't answer the question).

Sentence: With economic tension between the U . S . and Japan worsening , many Japanese had feared last week ' s visit from U . S . Trade Representative Carla Hills .<sep>Question: What has made economic tensions worse?
U . S . and Japan worsening ,