It is difficult to calculate the Earth's carrying capacity because there are lots of resources that we can use and their is so much land on the earth that hasn't been used, but at the same time some resources are running low, and some resources we have a lot of, like food, so that it is why it is difficult to calculate
In external respiration carbon dioxide move from capillaries to alveoli, while oxygen move from alveoli to capillaries in internal respiration.
Answer:
The "gills" and "tail" disappear before birth. Simple
A.
Due to the star not being very massive, when it finally collapses in on itself, it will produce a neutron star, not a black hole.
