What is the relationship between Sinopec and Beijing 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.

SHANGHAI Aug 21 Safety hazards have been found at almost 70 percent of firms handling dangerous chemicals inspected in Beijing since two massive blasts killed 114 people last week, including a branch of Asia's largest refiner Sinopec Corp, state media reported.

Answer: location_of_formation