The answer is "D"
The body's first line of defense is also known as Innate immunity and incudes mucous membranes. Both the intact skin and mucous membranes of the body offer a high degree of protection against pathogens.
A good example is the mucous membrane of the respiratory tract. It is lined up with cilia and covered with mucus. The coordinated beating of the cilia drives the mucus up to the nose and mouth where the trapped bacteria can be expelled.
(Lymph nodes and white blood cells belong to the second line of defense, not the first)
Answer:
I would say Phosphate Groups.
Explanation:
Nucleotides are joined together by covalent bonds between the phosphate group of one nucleotide and the third carbon atom of the pentose sugar in the next nucleotide.
D-low elevation and low relief
Answer:
the answer is B i did this test
Explanation: