question: earth:planet
choices.label: A B C D
choices.text: united kingdom:country London:United Kingdom highway:road island:mainland
explanation: "earth" is a kind of "planet", and "earth" is a thing. the "united kingdom" is a "country" and the "united kingdom" is a thing. "London" is part of "United Kingdom". "highway" is a kind of "road", and "highway" is a thing. "islands" refers to the naturally formed land surrounded by water in the ocean, rivers or lakes; "mainland" refers specifically to large areas of land and large basins bounded by mountains (such as north america, asia, etc.) "mainland" is land.
relation: earth planet R2.2
relation: united kingdom country R2.2
relation: London United Kingdom R2.2
relation: highway road R2.2
relation: island mainland R2.4