Pair 1 is incorrect: The Belle II experiment is a particle physics experiment designed to study the properties of B mesons. It is not related to artificial intelligence. Pair 2 s correct: Blockchain technology is the underlying technology behind cryptocurrencies like Bitcoin. It is a distributed ledger technology that ensures secure and transparent transactions. Pair 3 is incorrect: CRISPR-Cas9 is a gene-editing technology used in the field of molecular biology to edit genes. It is not related to particle physics. Therefore, only pair 2 is correctly matched.