Which part of the respiratory system is composed of a single layer of epithelial tissues surrounded by a network of capillaries?

alveoli

trachea

bronchiole

Which of the following is the source of energy for photosynthesis? a.) glucose b.) chlorophyll c.) carbon dioxide d.) sunlight

Once an egg cell is fertilized by sperm, the cell then, as the embryo develops, it receives nourishment and eliminates wastes by transferring substances from its blood to its mother's blood. a. becomes a fetus immediately and exits the womb b. begins to divide and implants itself in the wall of the uterus c. remains in the uterus without dividing for several months d. travels back to the ovaries until the fetus is developed

To confirm when to exclude children from school it’s recommended that you refer to guidelines from which of the following organizations