单项选择题
A．a signal sent by your brain B．the special function of the adrenal gland C．all stimulated parts of your body D．All of these
A．The adrenal gland is located on top of the kidney. B．Each kidney is composed of two adrenal glands. C．The medulla is inside the cortex. D．The cortex and the medulla have different functions.
A．a scientist as well as a naturalist B．a naturalist but not a scientist C．no more than a born naturalist D．first of all a scientist