What is a niche? (Select all that apply.) A. It is the primary and secondary consumer.

B. It is the number of organisms within the ecosystem.

C. It is the food an organism eats.

D. It is how the organism lives.

E .It is where the organism lives.
PLEASE HURRY!!

Over the last 90 years, scientists have added to the body of evidence supporting the big bang theory. what is the latest piece of evidence discovered in 2014?

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.

12. calculate the hydroxide ion concentration of a solution with ph = 3.25. show all calculations leading to an answer