18692
A variety of foreign " invaders " such as viruses , bacteria and other particulates e . g . , cigarette smoke , are inhaled , deposit on the airway surface and invade the " host . " Mucins produced by the surface airway epithelium and by the submucosal glands are secreted into the airway lumen .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
 None