1,000 years ago, the population was 3 Billion. How many million people is that?

3 thousand million

Explanation:

1 thousand million = 1 billion.

b because they naturally adapt to their environment plz mark brainliest

explanation:

science-ocean floors and habitats study guide by volleyballqueen3817 a major advance in ocean-floor mapping. list four sections of the ocean floor. algae that use sunlight to produce their own food through photosynthesis. all of the feeding relationships that exist in a habitat. drying out, predators, find food.