Simple. Air has mass. And if air has mass it also has weight. You can feel air when the wind blows. Or do an experiment. Weigh an empty container. Then pump it to a vacuum. Weigh it again. The difference is the weight of the air inside.
Answer:
It is made up of protons and neutrons
D. Lava plateau
They are formed when lava flows from the volcano & build up over time as the molten lava is deposited & cools.
Answer: no friction, metal
Explanation: yes
The most familiar non-vascular plants that contain simple conducting cells are Mosses. Most non vascular are bryophytes and are small in size, they lack vascular tissues and also lack true leaves, seeds, and flowers. Instead of roots, the have hair-like rhizoids that functions to anchor them to the ground and to absorb water and mineral salts from the soil. They are three types, mosses, hornworts and liverworts.