单项选择题

What are feelings for Most nonscientists will find this a strange question. Feelings just are. They justify themselves. Emotions give meaning and depth to life. They need serve no other purpose in order to exist. On the other hand, many evolutionary biologists, in contrast to animal behaviorists, acknowledge some emotions primarily for their survival function. For both animals and humans, fear motivates the avoidance of danger, love is necessary to care for young, and anger prepares one to hold ground. But the fact that a behavior functions to serve survival need not mean that that is why it is done. Other scientists have attributed the same behavior to conditioning, to learned responses. Certainly reflexes and fixed action patterns can occur without feeling or conscious thought. A gull chick peeks at a red spot above it. The parent has a red spot on its bill(喙); the chick peeks the parent’s bill. The gull parent feeds its chick when pecked on the bill. The baby gets fed. The interaction need have no emotional content.
Many evolutionary biologists believe that

A. emotions do not exist.
B. emotions contribute to survival.
C. emotions don’t give meaning and depth to life.
D. only humans are capable of emotions.
<上一题 目录 下一题>
热门 试题

单项选择题
Wind energy has been praised as cost-effective to produce clean energy as well as jobs. That promise, along with new government subsidies (补贴), has helped wind turbines (涡轮机) pop up on hills and fields throughout Americ
a. But not every environmentalist is happy about that development. Critics charge that wind-energy development can cause habitat fragmentation-a displacement of a species that can eventually reduce its numbers-as well as the deaths of birds and bats (a species that is especially vulnerable due to its low reproductive rates) that collide with the wind turbines’ massive blades. A 2007 study by the National Academy of Sciences puts the number of birds killed each year at about 20,000 to 30,000. That’s a low estimate, says Michael Fry of the American Bird Conservancy. According to his group, turbines kill three to 11 birds per megawatt of wind energy they produce.
According to critics, wind-energy development may causeA. the deaths of 20,000 to 30,000 birds.B. distinction of many species in the area.C. habitat fragmentation and deaths of birds.D. environment recovery from destruction.
单项选择题
Wisdom in old age depends on a fresh supply of new brain cells, a study in mice suggests.. When mature mice learn a new task, their newly generated brain cells are three times more active than their old ones, the researchers found. The findings add to a growing body of evidence that the adult brain needs a steady addition of new cells to maintain its mental faculties. Researchers found that mature mice’s brain cells are much more active than before when
A. they are transplanted with new brain cells.
B. they learn to do something new.
C. they gain weight in the body.
D. they get new cells from other mic
相关试题