The glands of the endocrine system secrete hormones into the bloodstream to maintain homeostasis and regulate metabolism.
Answer: the antigens identify the foreign invader
<span>The answer is through the placenta. The placenta is formed in the uterus of the pregnant woman. Its role is in the nourishment of the fetus. The placenta provides the fetus with nutrients and removes waste. The umbilical cord connects the placenta to the fetus and it serves as the transporting passageway. </span>
The answer I believe is c.secondary
Explanation:
I believe the answer is hepatitis B
