236436
Drive function depends on the head floating on an air bearing , or cushion of air , so it is not possible at this time to have the head simply operate in a vacuum .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities:  
Answer:
 None