A solid is hard and the molecules are packed together, a liquid can move around freely because the molecules aren't as packed together :)
1st law: Inertia, If you roll a ball it will not stop unless something blocks it by force.
2nd law: Force and Acceleration, when you’re riding a bike you are pushing the pedal with ur muscle which means you’re using force. Everytime you push the pedal the bike goes faster and faster which explains acceleration.
3rd law: Action and Reaction, If you run you’re feet pushes the ground (action) when your feet touches the ground it pushes you forward (reaction)
The answer you need is B. Pollution. Have in mind that Caves contain carvings and depictions that are formed from acids running through the limestones of the cave. The sulfuric acid that helped form the Lechugilla caves come from pollution.I hope this info can help you