163482
Basic state machine concepts Many software systems are event-driven , which means that they continuously wait for the occurrence of some external or internal event such as a mouse click , a button press , a time tick , or an arrival of a data packet .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 None