溃疡形成

例句：

1. 1. He developed a sore on his foot after a long day at work.
   他在工作了一整天后，脚上长了一个疮。
2. 2. The doctor prescribed medication to treat the ulcer.
   医生开了药来治疗这个疮。
3. 3. Ulcers can be caused by various factors such as stress and poor diet.
   溃疡可以由各种因素引起，比如压力和不良的饮食习惯。