Answer:
E. Variations in Earth's orbit occur gradually over 100,000 years.
Answer:
I think that birds have different bill lengths because of their habitats and their diet. Also natural selection and evolution has also played a factor due to the fact that birds have not always looked the way that they do now, for example the Archaeopteryx a bird that lived around the time of the dinosaurs had a shorter and more powerful bill to grind insects and small mammals
Explanation:
<span>Nitrogen fixation
This process creates organic compounds, including ammonium, that contribute to the growth of a plant in much the way fertilizer does. Many plants have evolved to facilitate nitrogen fixing bacteria in their roots as to promote production of these organic compounds when the soil quality is poor or lacking in these bacteria.</span>
This is put together perfectly.