What is the relationship between flying and aviation in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

So there's really not that much dependence on long-haul air travel for example, probably not that much difference on regional air travel; obviously, China's got a big aviation business and those planes are back flying and they're back flying at bigger numbers than they are in the US.

Answer: industry