A baby's immune system is not fully developed until he/she is about six months-old. In the meantime, pregnant mothers pass immunoglobulin antibodies from their bloodstream, through the placenta, and to the fetus. These antibodies are an essential part of the fetus's immune system. They identify and bind to harmful substances, such as bacteria, viruses, and fungi that enter the body. This triggers other immune cells to destroy the foreign substance.
The answer should be A.
The control variable is the experimental variable that remains unchanged throughout the experiment. Alice did change the angles where the light from the ray box struck the mirror and where the mirror reflected the light. She also changed the direction, but she never really changed the ray box.
Answer:
because of you family member
Explanation:
