研究背景从四年级起,我时常听见妈妈说她舌头痛、嘴唇痛。尤其是夏天,隔三岔五地看到妈妈痛苦的样子。为什么会这样呢?我试图帮妈妈找出原因。经过六个多月的观察,我发现,妈妈经常说自己舌头和嘴唇痛是因为妈妈犯了口腔溃疡。一开始,妈妈舌头上只是出现了一个椭圆形的白色斑点, Background From the fourth grade onwards, I often hear my mother say she has tongue pain and lip pain. Especially in summer, I saw the painful look of my mother at every turn. Why does this happen? I am trying to help my mom find out why. After more than six months of observation, I found that mothers often said that their tongue and lip pain were caused by moms having mouth ulcers. At first, only an oval white spot appeared on her tongue,