Question

15.what does nearly all the life on earth rely on?

Explanation:

Nearly all life on Earth relies on energy from the Sun. Photosynthetic organisms (like plants, algae) convert sunlight into chemical energy via photosynthesis, forming the base of food chains. Other organisms get energy by consuming these producers or other consumers. Even deep-sea life not directly using sunlight often depends on organic matter produced by photosynthesis elsewhere.

Answer:

Energy from the Sun (or sunlight)