Answer - Will try to Answer in simplest form with Reasoning. Since no one responded.
1.Solar-Thermal energy. For example the sun radiates thermal energy aka heat which then turns Liquid aka Water in gas molecules because they are escaping. (Evaporation)
2. Condensation happens when the water molecule vapor clump together before thermal energy can be separated by it. Such as the clouds which they form tiny vapor/mist. Thats why when your on a plane and when you hit thru that cloud at hundreds of mph. Your hitting water molecules lol.
Answer: plant tours
Explanation: operators work and keep it going and do not do tours
Answer: Possession of Valves
Explanation: Veins possess valves which ensures that blood flows in only one direction. Valves helps blood to flow back to the heart against gravitational force.
Arteries don't have valves because the pressure originating from the heart is capable of causing the blood to flow in one direction.
