Answer:
B) Valves closing
Explanation:
A healthy heart makes a lub-dub sound with each beat. This sound comes from the valves shutting on the blood inside the heart. The first sound (the lub) happens when the mitral and tricuspid valves close.
Breaking the body into systems is in most cases a lot easier for the students to understand instead of just doing it all at once
B. Subcutaneous
this means that the needle goes into the fat layer of the skin.
it does NOT go into the muscle.
hope this helps.
A surrogate mother donates her uterus to assist another woman who cannot become or stay pregnant because that another woman has some problem in getting her eggs produced or in getting fertilized.
Surrogate is a process in which a woman's egg is getting fertilized artificially with the sperm of a man who belongs to a couple. After the egg gets fertilized then, that fertilized egg is transferred to the uterus of a woman who belongs to above mention couple.
So a third person will help a couple to have a baby, and that third person is called a surrogate mother who donates his uterus. This surrogate mother is called a biological mother.
Learn more about surrogate mother here
brainly.com/question/951943
#SPJ4