mucus

例句：

1. 1. Mucus is a sticky substance that can coat the inside of your nose and throat.
   黏液是一种粘稠的物质，可以覆盖在鼻子和喉咙的内部。
2. 2. The doctor advised him to avoid touching his eyes with dirty hands.
   医生建议他避免用脏手触摸眼睛。
3. 3. The patient had developed a severe cough and was experiencing difficulty breathing.
   病人出现了严重的咳嗽并有呼吸困难。