q: Biomass is the total mass of living things at each what?
Options:
- (A) trophic level
- (B) important habitats
- (C) Energy.
- (D) food and shelter
- (E) Power plants
- (F) animals
- (G) body water
- (H) heat energy
a: (A)... Explanation: Biomass is the total mass of organisms at a trophic level. Most living things are called organisms. Biomass is the total mass of living things at a trophic level. That's why the answer is (A).

q: Plants cell walls are made of 
Options:
- (A) fiber
- (B) keratin
- (C) alveoli
- (D) cations
- (E) matter
- (F) CO 2
- (G) porous
- (H) Cane.
a: (A)... Explanation: Plants are multicellular eukaryotes with cell walls made of cellulose. Basically, fiber is cellulose . Plants cell walls are made of fiber. That's why the answer is (A).

q: What do animals do in the winter?
Options:
- (A) Release energy
- (B) running and lifting
- (C) it keeps an organism warm
- (D) adapt to warm weather
- (E) adapt to extreme heat
- (F) adapt to coolness
- (G) shed fur
- (H) by making heat
a: (F)... Explanation: Animals adapt to cold temperatures. Temperatures are moderate in summer and COLD in winter. Animals adapt to the coolness in the winter. That's why the answer is (F).

q: Marine animals find these to be a great source of food:
Options:
- (A) grain
- (B) nutrient
- (C) sponges
- (D) Energy.
- (E) sea vents
- (F) sodium
- (G) Energy
- (H) fungi
a:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
(C)... Explanation: Sponges are a source of food for many species of fish. Fish and other marine animals abound here. Sponges are a source of food for many marine animals. That's why the answer is (C).