A.ein, mit
B.ein, für
C.einen, mit
D.einen, für
第2题
A、Nein, ich wei? nicht.
B、Um halb drei.
C、Halb drei.
D、Tut mir leid. Meine Uhr geht nicht.
第4题
A.Her mother has bought too many things.
B.Her mother wants to talk to Mrs. Bell.
C.She is too heavy for her mother to carry.
第5题
In his sleep laboratory at the University of Chicago, Rechtschaffen places each rat on an enclosed turntable contraption that begins spinning whenever the rodent's brain waves suggest it is beginning to nod off-forcing the rodent to keep moving so that it doesn't bump into a wall. After about a week of enforced consciousness, the rat begins showing some signs of strain. Odd lesions break out on its tail and paws. It becomes irritable. Its body temperature drops even as it attempts to make itself warmer than usual. It eats twice as much food as normal but loses 10 to 15 percent of its body weight. After about 17 days of sleeplessness, the rat dies.
What kills it? "We don't know," says Rechtschaffen.
Thus it goes in the science of sleep. Rats can last about 16 days without eating, suggesting that sleep is nearly as vital to life as is food. Yet scientists are far from answering the seemingly simple question of what, exactly, sleep is good for.
Of course, there's no shortage of hypotheses; insomniacs hoping for some shut-eye might do well to count sleep theories instead of sheep. Many of the most popular theories are extensions of common-sense propositions from human experience. Since we feel rested after sleep, some researchers argue-that sleep must be for rest. Harold Zepelin, professor emeritus in psychology at Michigan's Oakland University, regards sleep as a period of mandatory energy conservation. "We can't afford to be active 24 hours per day," syas Zepelin, so evolution dictated this daily period of hibernation. (Some even argue that one reason sleep evolved in humans was to keep us unconscious and out of harm's way during the night, when we are not exactly the king of beasts.) Smaller animals such as rodents, which have high metabolisms and expend proportionately more energy to make up for the rapid loss of heat that is a geometric consequence of smallness, do tend to sleep more. Larger animals such as giraffes sleep less than five hours each day.
But the energy savings from sleep in large animals are so small it is hard to see why they would sleep at all by this theory. Humans save merely 120 kilocalories a night (about the equivalent of an apple) by sleeping rather than staying awake. Moreover, even hibernating animals arouse themselves from torpor to enter sleep and then fall back into hibernation, suggesting that there is a deeper need for sleep than a mere recharging of the body's batteries.
Dennis McGinty believes part of the function of sleep is to cool off the brain. The chief of neurophysiology research at Los Angeles's Sepulveda Veterans Hospital, McQmty points to a feedback loop in the brain that seems to trigger sleep when the brain gets too hot. When provided with a bar to increase cage temperature, rats that are kept awake jack up the heat about 10 degrees Celsius. By attempting to get warmer than usual, the rats may be hoping to trigger sleep-inducing neurons.
The phenomenon also occurs in humans. "If you exercise in the extreme heat, it practically knocks you out," McGinty notes. Well-trained athletes who are able to increase their body temperature during exercise—unlike us weekend workout warriors—sleep about one hour longer than normal. In essence, a jump in body temperature activates heat-sensitive neurons to slow down the body's metabolism—preferably by sleep—and thus cool down the brain. The body's minimum temperature comes during the deepest sleep, typically at around 5 a.m.
Which of the following can be the best tide for the passage?
A.The Sleep Laboratory at the University of Chicago.
B.The Experiment of Rats' Sleep.
C.What is Sleep for?
D.What can Sleeplessness result in?
第6题
A.has increase since the eighties
B.is at its worst in industrialized countries
C.results from poor relation between nations
D.is caused by human self-interest
第7题
(A) We're waiting for Joe.
(B) We're meeting in the main lobby.
(C) No, I'm Gladys. It's nice to meet you.
(18)
A.
B.
C.
第8题
A.Because it has a village.
B.Because it still travels on water.
C.Because it is near Dwarsgracht.
D.Because it has whisper boats.
第9题
Gespr?ch 2 - Arzt: Wer ist der ____? - Lin: Entschuldigung, ich habe mich versp?tet. - Arzt: Bitte ____ Sie sich! Wo tut es Ihnen _____? - Lin: Ich habe Kopfschmerzen und Husten. - Arzt: Wir müssen zuerst _____ messen. 38 Grad. Machen Sie den __ auf und sagen Sie ?Ah!“ - Lin: Herr Doktor, was fehlt mir? - Arzt: Sie haben eine Erk?ltung. In den letzten Tagen regnet es immer. Drau?en ist ziemlich kalt. - Lin: Ja, das habe ich schon _____ 2 Tagen. - Arzt: Ich _____ Ihnen ein Rezept. ___ Sie die Tabletten dreimal t?glich nach dem Essen. Sie müssen sich gut ___. - Lin: Vielen Dank, Herr Doktor. Auf Wiedersehen! - Arzt: Gute _____ ! Auf Wiedersehen.
第10题
After she graduated from high school, Mrs. Cox went on to college. Four years later, she received her bachelor's degree (B. A. ) in English and her teaching certificate. Then she was qualified to teach in the secondary schools of her state. In the summers, Mrs. Cox takes more classes. Someday she hopes to get a master's degree (M. A. ). With an M. A. , she will receive a higher salary.
The school day at Mrs. Cox's high school, like that in many high schools in the United States, is divided into six periods of one hour each. Mrs. Cox must teach five of these six periods. During her free period, which for her is from 2 to 3 p.m. , Mrs. Cox must meet with parents, order supplies, make out examinations, check assignments, and take care of many other things. In short, her free period isn't really free at all. Mrs. Cox works steadily from the time she arrives at school in the morning until the time she leaves for home late in the afternoon.
Mrs. Cox wants to be a teacher because______.
A.she likes teaching
B.she is a young girl
C.she has many problems to deal with
D.she doesn't mind what she is doing
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