Utilize the input text as a context reference, choose the right relationship between Sinopec and Beijing from the options. Options: 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