The word that describes how the planets are held together in Earth's solar system is "gravity."
The correct answer is "gravity." Gravity is the force that holds the planets in Earth's solar system together. To determine the correct answer, you could recall your knowledge about the fundamental forces of nature and the concept of gravity. Gravity is the force that attracts objects with mass towards each other, and it is responsible for keeping the planets in their orbits around the Sun. Additionally, you could consult reliable sources such as textbooks or educational websites that discuss the topic of gravity and its role in the solar system.
