question: duck:river
choices.label: A B C D
choices.text: ferris wheel:roller coaster comedy:drama aircraft:airport train:track
explanation: the activity places of "ducks" include the "river". "ducks" can also move on land. "ducks" are on the "river". the "ferris wheel" and the "roller coaster" belong to the same category, both referring to recreational facilities. "comedy" can be "drama" and "drama" can be "comedy". the activity places of "aircraft" include the "airport". aircraft" can also move on land. the activity places of the "train" include the "track", which is the only activity place for the "train".
relation: river duck R3.10
relation: ferris wheel roller coaster R2.4
relation: comedy drama R2.7
relation: airport aircraft R3.10
relation: track train R3.10