sial

例句：

1. 1. The doctor advised him to drink more water and avoid sipping his tea.
   医生建议他多喝水，避免小口喝茶。
2. 2. Sial is a common cause of dry mouth and bad breath.
   唾液是导致口干和口臭的常见原因。
3. 3.Sial is essential for digestion, as it helps break down food particles in the mouth.
   唾液对于消化至关重要，因为它有助于在口腔中分解食物颗粒。