Useful language oras. Gum牙龈 Saliva唾液 Plaque斑 Ename牙釉质 Moisture湿润 Phrases Be prone to sth易于∴ Periodontal pocket牙周袋Useful language Words: • Gum 牙龈 • Saliva 唾液 • Plaque 斑 • Enamel 牙釉质 • Moisture 湿润 Phrases: • Be prone to sth 易于…… • Periodontal pocket 牙周袋