Answer:
1. Sudden Infant Death Syndrome (SIDS) -> A condition in which the infant stops breathing and dies for no apparent reason.
2. Puberty -> The rapid physical change experienced due to hormonal and body changes during adolescence.
3. Shaken baby syndrome -> Occurs when a baby is shaken and results in hemorrhaging and swelling that can cause brain damage or even death.
4. Teratogen -> Any substance or agent that interferes with the normal development of a fetus in the womb.