The answer is Habitat. The brackish water environment is formed due to the mixing of fresh water from the river with the salty waters of the ocean. This habitat is significant for fishes that come to spawn and feed. Crabs, mosquitoes and birds can also be found in this environment.
The correct answer is: B. spinal cord
The nervous system can be divided into two subdivisions: the central nervous system (CNS) and the peripheral nervous system (PNS). The spinal cord and the brain are part of the CNS, whereas the PNS consists of the nerves that radiate from the CNS to all parts of the body. The PNS includes all neurons that sense and transmit information to the CNS.
The CNS controls thinking processes, movements, and registers the sensations throughout our body. Moreover, the PNS acts to transmit information from the CNS to all parts of the body.
The PNS is in turn divided into two main parts:
1-The Autonomic nervous system (ANS), which regulates involuntary functions and glands. The parasympathetic nervous system is one division of the ANS that controls visceral organs such as glands.
2- Somatic nervous system (SNS), which regulates voluntary muscle movement and transmits information from eyes, ears, and skin to the CNS.
Learn more in:
brainly.com/question/2156614?referrer=searchResults
<h2><u>Answer</u> :</h2>
The correct option is A. If a dominant allele is present, the recessive allele won’t be seen.
The dominant allele is the one which appear, and the recessive one isn't shown.
For example - If a person has 2 alleles of eye colour as B ( black ) and b ( brown ), in which black is dominant and the brown one is recessive, then the person will have black eye colour because only dominant allele shows its characteristics.
_____________________________

About 7 years hope I helped :)