I dont understand what they are asking please help!!

The energy of blowing wind can be harnessed to create electricity. why is wind considered a renewable energy source? a) wind does not cause destruction of the environment.b) wind turns the blades of a windmill that creates electricity.c) wind provides only a very small amount of electricity to the united states.d) wind comes from atmospheric conditions that are available indefinitely.

80 points pls brainliest 1. what does a red shift mean? blue shift? 2. describe the big bang theory. according to this theory, how old is the universe? 3. scientists believe the universe is expanding. what is the evidence that supports this? 4. describe a nebula. 5. describe the 3 types of galaxies. what is a barred spiral galaxy? 6. what is a light year? how far is alpha centauri from earth? 7. describe the universal law of gravitation. be sure to include gravitational force between two objects. 8. describe the planets’ orbits around the sun. 9. what is the asteroid belt? where is it located? 10. describe rotation and revolution of earth. what determines an earth day and year? 11. how do galaxies exist? 12. compare and contrast the inner and outer planets. 13. what causes the seasons?

The cretaceous period spanned the time interval between and 65 million years ago. 250 million 144 million 75 million 200 million