theory fruit理论成果theoryn.学说；理论；原理；意见theory of pitches--class音级集合理论theory of contestable market可竞争市场理论Theory of Hierarchical Needstheory of consumer rs budget消费者预算论theory of practical ontology实践本体论theory of increasing returns生产报酬递增论theory of industrial cluster产业集群理论theory of sectional catenary分段悬链线理论theory of social development社会发展理论theory of interest and taste“趣味说”