| natural resources(expression, nature, feature, detail) |
| ecological unit(expression, nature, feature, detail) |
| living thing(expression, nature, feature, detail) |
| living species(expression, nature, feature, detail) |
| natural phenomena(expression, nature, feature, environment, condition) |
| sea(noun, nature, environment, system) |
| animal species(expression, type, species, classification) |
| atmosphere(noun, nature, environment, system) |
| non-living thing(expression, nature, feature, detail) |
| physical phenomena(expression, nature, feature, detail) |
| plant species(expression, type, species, classification) |
| climate(noun, nature, environment, system) |
| earth(noun, nature, environment, system) |
| ground(noun, nature, environment, system) |
| natural system(expression, nature, feature, detail) |
| ocean(noun, nature, environment, system) |
| lake(noun, nature, environment, system) |
| pond(noun, nature, environment, system) |
| river(noun, nature, environment, system) |
| water(noun, nature, environment, system) |