Birds _____ when there isn’t enough food for them.

The birds also attack crops when the opportunity ________.

A arouses

B raises

C arises

D rises

A.mirror

B.sink

C.gide

D.wet

A.that

B.which

C.while

D.when

A、mirror

B、sink

C、glide

D、wet

The best solution to the problem of the spread of bird flu is ______.

A. to kill all the birds in an area where bird flu has been discovered

B. to kill all the chickens

C. to kill all the birds

D. to kill all the chickens when bird flu has been discovered

What is the lecture mainly about？

A．Methods of observing unusual animal behavior

B．A theory about ways birds attract mates

C．Ways animals behave when they have conflicting drives

D．Criteria for classifying animal behaviors

Passage Two

Questions 26 to 30 are based on the following passage.

Scientists have established that influenza viruses taken from man can cause the disease in animals. In addition，man can catch the disease from animals. In fact，a great number of wild birds seem to carry the virus without showing any evidence of illness. Some scientists conclude that a large family of influenza viruses may have evolved in the bird kingdom，a group that has been on the earth 100 million years and is able to carry the virus without contracting the disease. These are even convincing evidence to show that virus strains are transmitted from place to place and from continent to continent by migrating birds.

It is known that two influenza viruses can recombine when both are present in an animal at the same time. The result of such recombinations is a great variety of strains constraining different H and N spikes. This raises the possibility that a human influenza virus can recombine with an influenza virus form. a lower animal to produce an entirely new spike.

Research is underway to determine if that is the way that major new strains come into being. Another possibility is that two animal influenza strains may recombine in a pig，for example，to produce a new strain which is transmitted to man.

According to the passage，scientists have discovered that influenza viruses______.

A. cause ill health in wild birds

B. do not always cause symptoms in birds

C. are rarely present in wild birds

D. change when transferred from animals to man

members of the land community have no economic value. Yet these creatures are members of the biotic community. If its stability depends on its integrity, they are entitled to continuance. When one of these non-economic categories is threatened, and, if we happen to love it, we invent excuses to give it economic importance. At the beginning of century, songbirds were supposed to be disappearing. Scientists jumped to the rescue with some distinctly shaky evidence to the effect that insects would eat us up if birds failed to control them. The evidence had to be economic in order to be valid. It is painful to read these roundabout accounts today. We have no land ethic yet, but we have at least drawn nearer the point of admitting that birds should continue as a matter of intrinsic right, regardless of the presence or absence of economic advantage to us.

dings is a phenomenon known as the first-night effect. If a person stays in the same room the following night they tend to sleep more soundly. Yuka Sasaki and her colleagues at Brown University set out to investigate the origins of this effect.

Dr. Sasaki knew the first-night effect probably has something to do with how humans evolved. The puzzle was what benefit would be gained from it when performance might be affected the following day. She also knew from previous work conducted on birds and dolphins that these animals put half of their brains to sleep at a time so that they can rest while remaining alert enough to avoid predators (捕食者). This led her to wonder if people might be doing the same thing. To take a closer look, her team studied 35 healthy people as they slept in the unfamiliar environment of the universitys Department of Psychological Sciences. The participants each slept in the department for two nights and were carefully monitored with techniques that looked at the activity of their brains. Dr. Sasaki found, as expected, the participants slept less well on their first night than they did on their second, taking more than twice as long to fall asleep and sleeping less overall. During deep sleep, the participants’ brains behaved in a similar manner seen in birds and dolphins. On the first night only, the left hemispheres (半球、of their brains did not sleep nearly as deeply as their right hemispheres did.

Curious if the left hemispheres were indeed remaining awake to process information detected in the surrounding environment, Dr. Sasaki re-ran the experiment while presenting the sleeping participants with a mix of regularly timed beeps (蜂鸣声、of the same tone and irregular beeps of a different tone during the night. She worked out that, if the left hemisphere was staying alert to keep guard in a strange environment, then it would react to the irregular beeps by stirring people from sleep and would ignore the regularly timed ones. This is precisely what she found.

46. What did researchers find puzzling about the first-night effect？

A、To what extent it can trouble people.

C、What circumstances may trigger it.

B、What role it has played in evolution.

D、In what way it can be beneficial.

47. What do we learn about Dr. Yuka Sasaki doing her research？

A、She found birds and dolphins remain alert while asleep.

B、She found birds and dolphins sleep in much the same way.

C、She got some idea from previous studies on birds and dolphins

D、She conducted studies on birds and dolphins sleeping patterns.

48. What did Dr. Sasaki do when she first did her experiment？

A、She monitored the brain activity of participants sleeping in a new environment.

B、She recruited 35 participants from her Department of Psychological Sciences.

C、She studied the differences between the two sides of participants brains.

D、She tested her findings about birds and dolphins on human subjects.

49. What did Dr. Sasaki do when re-running her experiment？

A、She analyzed the negative effect of irregular tones on brains.

B、She recorded participants adaptation to changed environment.

C、She exposed her participants to two different stimuli.

D、She compared the responses of different participants.

50. What did Dr. Sasaki find about the participants in her experiment？

A、They tended to enjoy certain tones more than others.

B、They tended to perceive irregular beeps as a threat.

C、They felt sleepy when exposed to regular beeps.

D、They differed in their tolerance of irregular tones.

请根据短文内容，回答题。

Why Buy Shade-Grown Coffee？

When people argue about whether coffee is good for health, they&39;re usually thinking of the health of the coffee drinker. Is it good for your heart？ Does it increase blood pressure？ Does it help you concentrate？ However, coffee affects the health of the human population in other ways, too.＜br＞

Traditionally, coffee bushes were planted under the canopy (树冠) of taller indigenous (土生土长的) trees. However, more and more farmers in Latin America are deforesting the land to grow full-sun coffees. At first, this increases production because more coffee bushes can be planted if there aren&39;t any trees. With increased production come increased profits.＜br＞

Unfortunately, deforesting for coffee production immediately decreases local wildlife habitat.＜br＞

Native birds nest and hide from predators (捕食者) in the tall trees and migrating birds rest there.＜br＞

Furthermore, in the long term, the full-sun method also damages the ecosystem because more chemical fertilizers and pesticides are needed to grow the coffee. The fertilizers and pesticides kill insects that eat coffee plant, but then the birds eat the poisoned insects and also die. The chemicals kill or sicken other animals as well, and can even enter the water that people will eventually drink.＜br＞

Fortunately, farmers in Central and South America are beginning to grow more coffee bushes in the shade. We can support these farmers by buying coffee with such labels as "shade grown" and "bird friendly". Sure, these varieties might cost a little more. But we&39;re paying for the health of the birds, the land, ourselves, and the planet. I think it&39;s worth it.

What is the main idea of this passage？ 查看材料

A.Farmers are changing the way they grow coffee

B.Coffee is becoming more expensive to produce

C.Shade-grow coffee is more expensive than sun-grow coffee

D.People should buy shade-grown coffee