溃疡

例句：

1. 1. He has a stomach ulcer that causes him pain.
   他有一个胃溃疡，导致他疼痛。
2. 2. The doctor prescribed medication to treat his ulcer.
   医生开了药来治疗他的溃疡。
3. 3. Ulcers can be caused by stress and poor diet.
   溃疡可以由压力和不良饮食引起。