第八课节点传递数据那里，一直显示No module named 'cv_bridge'怎么办，开头不是已经调用了吗，试了各种办法没解决............               

求帮忙家人们

Traceback (most recent call last):
  File "/home/tang/dev_ws/install/learning_topic/lib/learning_topic/topic_webcam_pub", line 33, in <module>
    sys.exit(load_entry_point('learning-topic==0.0.0', 'console_scripts', 'topic_webcam_pub')())
  File "/home/tang/dev_ws/install/learning_topic/lib/learning_topic/topic_webcam_pub", line 25, in importlib_load_entry_point
    return next(matches).load()
  File "/usr/lib/python3.10/importlib/metadata/__init__.py", line 171, in load
    module = import_module(match.group('module'))
  File "/usr/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/home/tang/dev_ws/install/learning_topic/lib/python3.10/site-packages/learning_topic/topic_webcam_pub.py", line 12, in <module>
    from cv_bridge import CvBridge      # ROS与OpenCV图像转换类
ModuleNotFoundError: No module named 'cv_bridge'
[ros2run]: Process exited with failure 1