sentences: earth is greater in mass than mars
docs: sun is bigger_than_earth. star has much_more_mass_than_planet mars_gravity is weaker_than_earths. gravity_on_mars is less_than_of_earth. earth is bigger_than_moon. earth is smaller_than_sun. earth is bigger_than_on. mars is planet_just_like_earth. earth is larger_than_moon. sun is larger_than_earth.