阅读理解。 Why don"t birds get lost on their long migratory (迁居的) flights? Scienti

题型：同步题难度：来源：

阅读理解。    Why don"t birds get lost on their long migratory (迁居的) flights? Scientists have
puzzled over this question for many years. Now they"re beginning to fill in the blanks.
    Not long ago, experiments showed that birds rely on the sun to guide them during
daylight hours. But what about birds that fly mainly by night? Tests with artificial (人
造的) stars have proved conclusively that certain night-flying birds are able to follow
the stars in their long-distance flights.
    One such bird-a warbler (鸣禽)-had spent its lifetime in a cage and had never flown
under a natural sky. Yet it showed an inborn ability to use the stars for guidance. The
bird"s cage was placed under an artificial star-filled sky at migration time. The bird
tried to fly in the same direction as that taken by his outdoor cousins. Any change in
the direction of the make-be-live stars caused a change in the direction of his flight.
    Scientists think that warblers, when flying in daylight, use the sun for guidance.
But the stars are apparently their principal means of navigation (导航). What do they do
when the stars are hidden by clouds? Apparently, they find their way by such landmarks as
mountain ranges, coast lines, and river courses. But when it"s too dark to see these, the
warblers circle helplessly, unable to get their direction. 1. The reasons why birds don"t get lost on migratory flights _____. [     ]
A. have been known to scientists for many years
B. have only recently been discovered
C. are known by everyone
D. will probably remain a mystery 2. Warblers migrate _____. [     ]
A. from North America to South America
B. only once during their lifetime
C. using what is apparently an inborn navigational ability
D. when they are freed from their cages 3. When the stars are hidden by clouds, warblers find their way by _____. [     ]
A. an artificial star
B. their inborn ability
C. some landmarks
D. wind 4. This article is a good example of the way scientists _____. [     ]
A. jump to conclusions
B. discover workable (可行的) answers to general questions by studying particular cases
C. find a law and then investigate (调查)
D. are disappointed by the habits of animals

答案

1-4: BCCB

举一反三

阅读理解。    Animals like the lion are known as carnivorous (meat-eating) animals. They feed on
smaller animals. But many other animals eat grass or plants. They are called herbivorous
(plant-eating) animals.
    You may be surprised to learn that there are carnivorous plants as well as carnivorous
animals. Plants that grow in poor soil need other food. They trap (catch by a trick) small
insects (昆虫) and take their bodies as food.
    The pitcher plant (猪笼草) is a common carnivorous plant. This plant has a clever trap
like a pitcher or jar. It even has a lid to keep out of the rain. The mouth of the pitcher
is covered with something sweet like honeydew (蜜露). Insects come to the plant to feed on
the honeydew. When they have eaten all that is round the mouth, they go into the pitcher
to look for more. There is more honeydew deep in the pitcher and they go down to feed on
it. The inner (里面的) wall of the pitcher is covered with fine hairs. These hairs point
downwards so that the insects cannot climb out of the pitcher. They are trapped in it.
They die there, and their bodies are taken as food by the plant. 1. Animals are divided into two kinds _____. [     ]
A. carnivorous animals and meat-eating animals
B. herbivorous animals and plant-eating animals
C. carnivorous animals and herbivorous animals
D. meat animals and plant animals 2. The pitcher plant uses _____ to catch insects. [     ]
A. a trap like a pitcher or jar
B. something sweet like honeydew
C. downward-pointing hairs in the inner wall
D. all of the above 3. Which of the following is NOT true? [     ]
A. Tigers, lions and other meat-eating animals are called carnivorous animals.
B. Zebras, elephants and common farm animals are known as herbivorous animals.
C. All plants get food only from the soil.
D. It is something like honeydew in the pitcher that insects come to food on. 4. From this passage, we can mainly learn that _____. [     ]
A. Not all plants are carnivorous
B. All plants are herbivorous
C. Not all animals are carnivorous
D. Carnivorous plants can also be found

题型：同步题难度：| 查看答案

阅读理解。    The new iPhone 3G should please everyone. Its look and feel are only slightly improved,
but a faster network loads Web pages more quickly, true GPS functionality allows it to easily
find places nearby, and the new $199 price (down from $400) makes it an affordable luxury.
    Before deciding whether to buy, however, make sure you can actually take advantage of
the iPhone 3G"s high-speed data network. 3G stands for third-generation, which in non-geek
speak translates to Web pages and mail messages that, ideally, load about three times faster
than on the original iPhone. Even better, 3G coverage enables you to make a phone call and surf
the Web at the same time. That"s great, if you live or work in a place where the 3G network of
AT&T (美国电话电报公司) (the sole wireless carrier of the iPhone) is active. That"s not so
great in cities like New York where AT&T"s cellular coverage is awful. As one of my colleagues
in New York City, who bought the original iPhone, commented, "It"s just a toy. You can"t make
phone calls on it, so I carry my Verizon phone with me all the time."
    The real fun begins when you tap on the icon called "App Store" and start browsing the hundreds
of add-on applications that have been developed just for the iPhone. You"ll find tons of games (I like
JirboBreak, a free game inspired by the Atari classic Breakout) and mobile versions of popular
websites like Pandora, Facebook, MySpace and the New York Times. Most apps will cost you,
but the vast majority are $9.99 or less. The apps work on the old iPhones too, but you"ll enjoy them
a lot more on the iPhone 3G because many of the programs, including Yelp (local business reviews),
Whrrl (mobile social networking) and UrbanSpoon (restaurant reviews), use your exact location-
provided by the iPhone 3G"s GPS chip-to make recommendations. The apps also load much faster
over the 3G network. 1. The new iPhone 3G has following features except that _____.[     ]
A. It looks and feels better
B. It has a faster network
C. It is easy to locate a place
D. It is too expensive for people to buy 2. Why do one of my colleagues carry Verizon phone with him all the time? [     ]
A. Because iPhone 3G is just a toy.
B. ecause he prefers Verizon phone better.
C. Because AT&T"s cellular coverage is terrible there.
D. Because Verizon phone enables him make a phone call and surf the Web at the same time. 3. Which of the following statements is NOT true according to the passage. [     ]
A. App Store will offer you great fun.
B. many apps have been developed for the iPhone.
C. Most apps are very expensive.
D. Pandora, Facebook, MySpace and the New York Times are popular websites. 4. From the passage we know that the attitude of the author toward iPhone 3G is _____. [     ]
A. doubtful
B. appreciative
C. optimistic
D. pessimistic

题型：0123 期末题难度：| 查看答案

阅读理解。    Birds that are half-asleep-with one brain hemisphere (半球) 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 groups led researchers to predict extra alertness in the
end-of-the-row sleepers which tend to be attacked more easily. 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 napping at the end of the line depend on single-hemisphere sleep, rather
than total relaxation, more often than inner ducks did. Turning 16 birds through the
positions in a four-duck row, the researchers found that compared with 12 percent for
birds in internal spots, outer birds half-asleep during some 32 percent of napping time.
    "We believe this is the first evidence for an animal behaviorally controlling sleep
and wakefulness at the same time in different regions of the brain," the researchers say.
    The results provide the best evidence for a long-standing assumption that single-
hemisphere sleep evolved as creatures scanned for enemies. The preference for opening an
eye on the lookout side could be widespread, he predicts. He"s seen it in a pair of birds
napping side-by-side in the zoo and in a single pet bird sleeping by a mirror. The mirror
-side eye closed as if the reflection were a companion and the other eye stayed open.
    Useful as half-sleeping might be, it"s only been found in birds and such water animals
as dolphins, whales, and seals. Perhaps keeping one side of the brain awake allows a
sleeping animal to surface occasionally to avoid drowning.
   Studies of birds may offer unique insights into sleep. Jerome M. Siegel of the UCLA
says he wonders if birds" half-brain sleep "is just the tip of the iceberg." He
supposes that more examples may turn up when we take a closer look at other species. 1. According to the passage, birds often half sleep because _____. [     ]
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 2. What is implied about the example of a bird"s sleeping in front of a mirror? [     ]
A. An imagined companion gives the bird a sense of security.
B. Birds prefer to sleep in pairs for the sake of their security.
C. The phenomenon of birds napping in pairs is widespread.
D. A single pet bird enjoys seeing its own reflection in the mirror. 3. While sleeping, some water animals tend to keep half awake in order to _____. [     ]
A. alert themselves to the approaching enemy
B. emerge from water now and then to breathe
C. be sensitive to the ever-changing environment
D. avoid being swept away by rapid currents 4. By saying "just the tip of the iceberg", Siegel suggests that _____. [     ]
A. half-brain sleep has something to do with icy weather
B. the mystery of half-brain sleep is close to being solved
C. most birds living in cold regions tend to be half sleepers
D. half-brain sleep may exist among other species

题型：0123 期末题难度：| 查看答案

阅读理解。Below is adapted from an English dictionary.

题型：0123 期末题难度：| 查看答案

最新试题

热门考点

超级试练试题库

figure/fīg[/ noun, verb ●noun 1. [C, often pl.] a number representing particular amount, especially one given in official information: the trade /sales figures 2. [C] a symbol rather than a word representing one of the numbers between 0 and 9: a six-figure salary 3. [pl] (informal) the area of mathematics that deals with adding, multiplying, etc 4. a person of the type mentioned: Gandhi was both a political and a religious figure in Indian history. 5. the shape of a person seen from a distance or not clearly 6. a person or an animal as shown in art or a story: a wall with five carved figures in it 7. [C] the human shape, considered from the point of view of being attractively thin: doing exercise to improve one"s figure 8. [C] a pattern or series of movements performed on ice: figure-skating [IDM] be/become a figure of fun: be/ become sb. that others laugh at cut a… figure: (of a person) to have a particular appearance He cut a striking figure in his dinner jacket. put a figure on sth.: to say the exact price or number of sth.	a fine figure of man/woman: a tall, strong-looking and well-shaped person figure of speech: a word or phrase used in a different way from its usual meanings in order to create a particular mental image or effect figurehead: someone who is the head or chief in name only (with no real power or authority) ●verb 1. to think or decide that sth. will happen or is true: I figured that if I took the night train, I could be in Scotland by morning. 2. to be part of a process, situation, etc. especially an important part: My opinion of the matter didn"t seem to figure at all. 3. to calculate an amount or the cost of sth.: We figured that attendance at 150,000. [PHRV] 1. figure in: to include (in a sum): Have you figured in the cost of hotel? 2. figure on: to plan on; to expect sth. to happen: I haven"t figured on his getting home too late. 3. figure out: to work out; understand by thinking: Have you figured out how much the trip will cost? [IDM] It/That figures! (informal): That seems reasonable, logical and what I expect.
阅读理解。
Can you remember a morning when you"ve woken up to the ring of your alarm clock and wished you could stay in bed? You haven"t slept well, your hair is a mess. Worse, you can"t stop yawning. Yawning is universal to humans and many animals. Cats, dogs and fish yawn just like humans do! Yawning is an involuntary (无意识的,不自觉的) action during which you open your mouth and breathe deeply. The average duration of a yawn is about 6 seconds. The purpose and cause of yawning are still a mystery. Scientists are not sure what causes a yawn. People yawn when they are tired or bored, but they also yawn when they aren"t. There are many ideas explaining why we yawn. One idea is that yawning is a way for the body to become more alert by taking in more oxygen. A yawn increases the heart rate, forces carbon dioxide out of the lungs and blood stream, and brings oxygen to the brain. But one study showed that volunteers given a lot of oxygen did not yawn any less than before, while those given a lot of carbon dioxide did not yawn more. Another idea is that early humans used yawning as a form of communication. If one decided it was time to sleep, they would tell the others by yawning and they would do it in return to show they agreed. A third explanation comes from psychology professor Gordon Gallup of University at Albany in New York. He said that as people yawn, they cool off their brains. "Brains are like computers." he said. "They only operate efficiently and effectively when they"re cool. Many things connected to yawning, like being tired, make the brain hot, and yawning can reduce the heat." Scientists have sent people into space, and created terrible nuclear weapons, but there are lots of seemingly simple things, such as why we yawn, or hiccup, that they can"t figure out. Next time you are in class in the morning, let out a big yawn and watch to see how many of your classmates yawn in response!
1. What"s the purpose of the description of how bad you may feel when you"re woken up in the morning?
[ ]
A. To explain why humans yawn. B. To explain how humans start yawning. C. To lead into the topic of yawning. D. To complain about being woken up by the clock.
2. Which is not among the possible reasons for yawning mentioned in the passage?
[ ]
A. A way to show that you feel hot. B. A way to get rid of carbon dioxide. C. A way to cool off your brain. D. A way to communicate.
3. In which situation are you likely to yawn?
[ ]
A. When you feel sleepy. B. The weather is hot. C. Someone else yawns near you. D. When you breathe in a lot of carbon dioxide.
4. What can we learn from the passage?
[ ]
A. The real reason why humans and most animals yawn. B. Hiccups are an involuntary human action similar to yawns. C. The more an action can be studied, the easier it is to research. D. Finding out why humans yawn should be easier than sending people into space.