Birds and humans are theorized to have a common ancestor because they have homologous structures. Which evidence best supports this theory? They both have tails as embryos. They each have vestigial structures. They have analogous structures. They have different forms as adults.

All vaccination should(n’t) be mandatory! 1.at least 5 sentences explaining 2.why? 3.in the end summarize the sentence

Natural resources are any materials that humans obtain from the earth to meet our wants and needs.

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?