单项选择题
In this passage, the author is mainly discussing the function of （）
A．the human brain B．glands and systems in the body C．the cortex of the adrenal gland D．the medulla of the adrenal gland
单项选择题 It can he inferred from the passage that the author was （）
单项选择题 According to the author, a born naturalist should first of all be （）
单项选择题 The first paragraph tells us the author （）
