[单项选择] In a purely biological sense, fear begins with the body’’s system for reacting to things that can harm us—the so-called fight-or-flight response. "An animal that can’’t detect danger can’’t stay alive, "says Joseph LeDoux. Like animals, humans evolved with an elaborate mechanism for processing information about potential threats. At its core is a cluster or neurons (神经元) deep in the brain known as the amygdala(扁桃核). LeDoux studies the way animals and humans respond to threats to understand how we form memories of significant events in our lives. The amygdala receives input from many parts of the brain, including regions responsible for retrieving memories. Using this information, the amygdala appraises a situation—I think this charging dog wants to bite me—and triggers a response by radiating nerve signals throughout the body. These signals produce the familiar signs of distress; trembling, perspiration and fast-moving feet, just to name three. This fear mechanism is crit
A. the biological process in which human beings’’ sense of self-defense evolves
B. the instinctive fear human beings feel when faced with potential danger
C. the act of evaluating a dangerous situation and making a quick decision
D. the elaborate mechanism in the human brain for retrieving information

[单项选择] In a purely biological sense, fear begins with the body’’s system for reacting to things that can harm us—the so-called fight-or-flight response. "An animal that can’’t detect danger can’’t stay alive, "says Joseph LeDoux. Like animals, humans evolved with an elaborate mechanism for processing information about potential threats. At its core is a cluster or neurons (神经元) deep in the brain known as the amygdala(扁桃核). LeDoux studies the way animals and humans respond to threats to understand how we form memories of significant events in our lives. The amygdala receives input from many parts of the brain, including regions responsible for retrieving memories. Using this information, the amygdala appraises a situation—I think this charging dog wants to bite me—and triggers a response by radiating nerve signals throughout the body. These signals produce the familiar signs of distress; trembling, perspiration and fast-moving feet, just to name three. This fear mechanism is crit
A. reactions of humans and animals to dangerous situations are often unpredictable
B. memories of significant events enable people to control fear and distress
C. people’’s unpleasant memories are derived from their feelings of fear
D. the amygdala plays a vital part in human and animal responses to potential danger

[单项选择] Although fear of math is not a purely female phenomenon, girls tend to drop out math sooner than boys, and adult women experience an aversion to math and math-related activities that is akin to anxiety. A 1972 survey of the amount Of high school mathematics taken by incoming freshmen at Berkeley revealed that while 57 percent of the boys had taken four years of high school math, only 8 percent of the girls had had the same amount of preparation. Without four years of high school math, students at Berkeley, and at most other colleges and universities, are ineligible for the calculus sequence, unlikely to attempt chemistry or physics, and inadequately prepared for statistics and economics. Unable to elect these entry-level courses, the remaining 92 percent of the girls will be limited, presumably, to the career choices that are considered feminine: the humanities, guidance and counseling, elementary school teaching, foreign languages, and the fine arts. Boys and girls may b
A. girls have more anxiety
B. they are born different with respect to math
C. girls are mature later than boys
D. boys are more intelligent than girls at different age levels