Answer:
Organic molecules produced from spontaneous synthesis or from meteorites
Explanation:
Acidic substance(s):
Vinegar contain acetic acid
Tomato Juice contain citric acid
Basic substance(s):
Baking Soda contains Sodium Carbonate
Neutral Substance(s):
In the process of producing sugar, the sugar cane juice is acidic but goes through a process where it's acidity is neutralized and as such the crystalline sugar ends up neutral
Answer:
Mechanical barriers — which include the skin , mucous membranes , and fluids such as tears and urine — physically block pathogens from entering the body. Chemical barriers — such as enzymes in sweat , saliva , and semen — kill pathogens on body surfaces.
Answer:
the umbilical cord is connected to both the mother and the unborn child and so tranfers nutrients from the mothers blood to that of the baby's blood