निम्नलिखित में से किसे जीवाश्म ईंधन (fossil fuel) के रूप में वर्गीकृत नहीं किया जाता है?

What is considered the primary source of energy for most ecosystems on Earth?

Why is thermal power not considered a renewable energy source?

Which form of energy is primarily caused by the gravitational pull of the Sun and the Moon on the Earth?