Given the input sentence, please extract the subject and object containing a certain relation in the sentence according to the following relation types, in the format of "relation1: word1, word2; relation2: word3, word4". Relations include: 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.

Low production at a single Exxon Mobil refinery in Southern California is keeping gasoline prices higher than they are in many other parts of the United States, where a domestic oil boom has driven prices lower over the last year, according to an article in the Los Angeles Times.

Answer: product_or_material_produced: Exxon, gasoline; product_or_material_produced: Mobil, gasoline