chronic ulcer of skin

例句：

1. 1. The patient's chronic ulcer had been unresponsive to treatment for months.
   患者的慢性溃疡几个月来对治疗没有反应。
2. 2. The doctorprescribed a new medication to treat the patient's chronic ulcer.
   医生为患者开了一种新的药物来治疗他的慢性溃疡。
3. 3. The patient was referred to a specialistfor further treatment of his chronic ulcer.
   患者被转介给专家，以便进一步治疗他的慢性溃疡。