About 75 percent of oral cancers are caused by smoking and drinking alcohol. Oral cancer is lethal more often than it needs to be because people tend to ignore symptoms.

• 大约75%25的口腔癌是由吸烟和饮酒引起的。口腔癌的致死性之所以比该病应有致死性高，是因为人们常常忽视了症状。