question: mekong river:cross-border river
choices.label: A B C D
choices.text: eiffel tower:church qinghai lake:inland lake british:western european big ben:arc de triomphe
explanation: the "mekong river" originates from the northeastern slope of tanggula mountain in china. it is called the lancang river in china, and the section of the river that flows into the indo-china peninsula is called the mekong river. therefore, the "mekong river" is a "cross-border river", and the "mekong river" is a specific thing. "eiffel tower" is not a "church". "qinghai lake" is a chinese "inland lake", and "qinghai lake" is a specific thing. "british" belongs to "western european , but "british" is a collective concept. "big ben" and "arc de triomphe" are two different buildings, but in addition to "big ben" and "arc de triomphe", leaning tower of pisa is also a building.
relation: mekong river cross-border river R2.2
relation: qinghai lake inland lake R2.2
relation: british western european R2.2
relation: big ben arc de triomphe R2.6