更多"Birds that are literally half-aslee"的相关试题:
[单项选择] Birds that are literally half-asleep -- with one brain hemisphere alert and the other sleeping -- control which side of the brain remains awake, according to a new ’’study of sleeping ducks.
Earlier studies have documented half-brain sleep in a wide range of birds. The brain hemispheres take turns sinking into the sleep stage characterized by slow brain waves. The eye controlled by the sleeping hemisphere keeps shut, while the wakeful hemisphere’’s eye stays open and alert. Birds also can sleep with both hemispheres resting at once.
Decades of studies of bird flocks led researchers to predict extra alertness in the more vulnerable, end-of-the row sleepers. Sure enough, the end birds tended to watch carefully on the side away from their companions. Ducks in the inner spots showed no preference for gaze direction.
Also, birds dozing (打盹) at the end of the line resorted to single-hemisphere sleep, rather than total relaxation, more often than inner ducks did. Rotating 1
A. they have to watch out for possible attacks
B. their brain hemispheres take turns to rest
C. the two halves of their brain are differently structured
D. they have to constantly keep an eye on their companions
[单项选择]Birds that are literally half asleep—with one brain hemisphere alert and the other sleeping—control which side of the brain remains awake, according to a new study of sleeping ducks.
Earlier studies have documented half brain sleep in a wide range of birds. The brain hemispheres take turns sinking into the sleep stage characterized by slow brain waves. The eye controlled by the sleeping hemisphere keeps shut, while the wakeful hemisphere’s eye stays open and alert. Birds also can sleep with both hemispheres resting at once.
Decades of studies of bird flocks led researchers to predict extra alertness in the more vulnerable, end-of-the-row sleepers. Sure enough, the end birds tended to watch carefully on the side away from their companions. Ducks in the inner spots showed no preference for gaze direction.
Also, birds dozing at the end of the line resorted to single hemisphere sleep, rather than total relaxation, more often than inner ducks did. Rotating 16 birds through th
A. half brain sleep is found in a wide variety of birds
B. half brain sleep is characterized by slow brain waves
C. birds can control their half brain sleep consciously
D. birds seldom sleep with the whole of their brain at rest
[单项选择]Birds that are literally half asleep--with one brain hemisphere alert and the other sleeping --control which side of the brain remains awake, according to a new study of sleeping ducks.
Earlier studies have documented half brain sleep in a wide range of birds. The brain hemispheres take turns sinking into the sleep stage characterized by slow brain waves. The eye controlled by the sleeping hemisphere keeps shut, while the wakeful hemisphere’s eye stays open and alert. Birds also can sleep with both hemispheres resting at once.
Decades of studies of bird flocks led researchers to predict extra alertness in the more vulnerable, end of the row sleepers. Sure enough, the end birds tended to watch carefully on the side away from their companions. Ducks in the inner spots showed no preference for gaze direction.
Also, birds dozing at the end of the line resorted to single hemisphere sleep, rather than total relaxation, more often than inner ducks did. Rotating 16 birds t
A. half brain sleep is found in a wide variety of birds.
B. half brain sleep is characterized by slow brain waves.
C. birds can control their half brain sleep consciously.
D. birds seldom sleep with the whole of their brain at rest.
[单项选择]
Birds that are literally half-asleep---with one brain hemisphere alert and the other sleeping- control which side of the brain remains awake, according to a new study of sleeping ducks.
Earlier studies have documented half-brain sleep in a wide range of birds. The brain hemi- spheres take turns sinking into the sleep stage characterized by slow brain waves. The eye con- trolled by the sleeping hemisphere keeps shut, while the wakeful hemisphere’ s eye stays open and alert. Birds also can sleep with both hemispheres resting at once.
Decades of studies of bird flocks led researchers to predict extra alertness in the more vulnerable, end-or-the-row sleepers. Sure enough, the end birds tended to watch carefully on the side away from their companions. Ducks in the inner spots showed no preference for gaze direction.
Also, birds dozing(打盹) at the end of the line resorted to single-hemisphere sleep, rather than total relaxation, more often than inner ducks
A. exploit the weaknesses in human nature
B. are targeted at different audiences
C. appear at different times of the day
D. have monopolized the talk show circuit
[填空题]
Wild ducks and other migratory (迁移的) birds could be important
carriers of deadly bird flu, researchers say. Even so. the infectious-disease
experts say there is no solid basis for killing wild birds to protect poultry
and minimize the risk. of human infection.
The European team
investigating the global spread of the It5N1 strain of avian influenza (禽流感)
says certain duck species may be infecting wild bird populations. Geese and
wading birds are also possible vectors (带菌者) of the virus, the team
says.
The team’s study was led by Bjorn Olsen of Umea University
in Sweden~ Olsen runs Europe’s largest wild-bird flu monitoring
program.
Studies have shown that influenza viruses in lake
water, generally passed via bird feces(粪), can stay infectious for up to 30
days. The migration or feeding behavior of dabbling ducks could at least
partially explain the spread of the H5NI strain of bird flu, the researchers
add.
This group of duc
