症结

例句：

1. 1. The solution to the problem lies in identifying the root cause of the difficulty.
   解决问题的关键在于找出困难的根源。
2. 2. The company's success is largely due to its ability to identify and address key issues.
   公司的成功很大程度上归功于它能够识别并解决关键问题的能力。
3. 3. The doctor diagnosed the patient's condition at the root of the illness.
   医生在疾病的根本原因上诊断了病人的状况。