sentences: heat sky trilobite are pathway of heat land
docs: heat_of_formation is heat. global_warming is heating. trilobite is arthropod. heat_of_dissociation is heat. heat_shell is bullet. space_heater is heating_device. global_warming is heating_air. heat_stroke is hyperthermia. sun's_light is what_heats_earth. geothermal_energy is heat.