Chew betel nut. Most of the studios I see are from Hunan, which is very stressful. Most of them are from eat areca, and the teachers eat very hard. Every year, from entering the studio in July to leaving the studio in March, the consumption of betel nuts has doubled. My head teacher is covered with sores every year 10, so it doesn't matter what medicine he takes. Students began to improve in March, but did not improve in July, and they grew new. Really worried about his health.