Answer:
it's answer a
carbohydrates
Explanation:
a carbohydrate (e.g. starch, cellulose, or glycogen) whose molecules consist of a number of sugar molecules bonded together.
Your answer is correct. Chitin provide the strength to insect exoskeletons. Cellulose is the strength for plant. Starch and glycogen are energy sources for life.
Answer:
A. Molecules from food and molecules of oxygen move from the mouth and the nose to cells of the body through a series of blood vessels, including veins, arteries, and microscopically small blood vessels (capillaries), that extend throughout the body.
Explanation: