The main food sources of the birds( the plentiful recourses within the environment occupied by the species)
Evidence of evolution. Scientists support the evidence of evolution because of the adaptations organisms used to have in the past compared to the present. For example, humans have organs in their bodies they don't need, but must have been used in ancient times. They can also find that humans have a common ancestor such as monkeys because of the DNA similarities and many adaptations. Hopefully this answered most of your question.
Answer: Option A "Choroid plexus".
Explanation:
Cerebrospinal fluid can be defined as the fluid that is found in the brain and spinal cord of human beings. It is a clear and colorless fluid.
The production of cerebrospinal fluid takes place by the specialized ependymal cells that lies in the choroid plexuses which is present in the ventricles of brain.
The amount of cerebrospinal fluid in a day is 500mL. This fluid acts as cushion that protects the brain from mechanical and immunological protection.
Hence, the correction answer is option A
A convergent boundary is an area on Earth where two or more lithospheric plates collide. One plate eventually slides beneath the other causing a process known as subduction. The subduction zone can be defined by a plane where many earthquakes occur, called the Benioff Zone.