Even though she could see herself in the mirror of the dressing table, she was never visib
________ has finished the work ahead of time will be rewarded with a onemonth holiday. |
[ ] |
A. Those who B. Anyone C. Whoever D. No matter who |
A、Statistics showing that it takes less time for the same student to understand the target materials than he previously did of a similar piece of material.
B、Students’ own testimony.
C、The causes behind this improvement of efficiency.
D、A contrast group that shows a student following the old teaching method not doing as well as the tested student.
Why is such a basic health service so easily knocked out? Mainly because private companies have had little incentive to pursue it. To create a single dose of flu vaccine, a manufacturer has to grow live virus in a 2-week-old fertilized chicken egg, then crack the egg, harvest the virus and extract the proteins used to provoke an immune response. Profit margins are narrow, demand is fickle and, because each year's flu virus is different, any leftover vaccine goes to waste. As a result, the United States now has only two major suppliers ( Chiron and Aventis Pasteur)--and when one of them runs into trouble, there isn' t much the other can do about it. "A vaccine maker can't just call up and order 40 million more fertilized eggs," says Manon Cox, of Connecticut-based Protein Sciences Corp. "There's a whole industry that's scheduled to produce a certain number of eggs at a certain time. "
Sleeker technologies are now in the works, and experts are hoping that this year's fiasco will speed the pace of innovation. The main challenge is to shift production from eggs into cell cultures--a medium already used to make most other vaccines. Flu vaccines are harder than most to produce this way, but several biotech companies are now pursuing this strategy, and one culture-based product (Solvay Pharmaceuticals' Invivac) has been cleared for marketing in Europe.
For Americans, the immediate challenge is to make the most of a limited supply. The government estimates that 95 million people still qualify for shots under the voluntary restrictions announced last week. That' s nearly twice the number of doses that clinics will have on hand, but only 60 million Americans seek out shots in a normal year. In fact, many experts are hoping the shortage will serve as an awareness campaign--encouraging the people who really need a flu shot to get one.
Shortages of flue vaccine show that ______.
A.America relies too much on foreign suppliers
B.the demand of flue vaccines is high this year
C.quality problem is a serious problem in flu vaccine production
D.the supply of flu vaccines is rather weak and America has no back-up measures to make it up
Directions: Answer questions 71-80 by referring to the following games.
Note: Answer each question by choosing A, B or C and mark it on ANSWER SHEET 1. Some choices may be required more than once.
A = Hallucinogens B = Cocaine C = Alcohol Which drug...
may slow down body function? 71.______
can lead to the drivers' distorted perception of reality? 72.______
may influence the drivers' vision negatively? 73.______
is psychologically addictive to those chronic uses? 74.______
can cause the impairment of driving? 75.______
can cause difficulty focusing? 76.______
can make drivers dissociate from the environment? 77.______
can make drivers easily irritated? 78.______
can affect how drivers think, feel and act? 79.______
may stimulate drivers to flee in their cars? 80.______
A
The term "hallucinogen" describes any drug that radically changes a person' s mental state by distorting the perception of reality to the point where, at high doses, hallucinations occur. Normal sensitivity is usually restored after abstaining for several consecutive days. Chronic users may also become psychologically dependent on hallucinogens. Psychological dependence exists when a drug is so central to a person's thoughts, emotions, and activities that the need to continue its use mats to a craving or compulsion.
According to the National Survey on Drug Abuse, four million Americans used hallucinogens in 1982. Presumably most of them drive. Paul Fishbein of Phoenix House in New York City, one of the nation' s largest residential drug-treatment facilities, describes the driver-impairing impact of phencyclidine(PCP or " angel dust"), a depressant with hallucinogenic effects; "After the first few hits(drags)of a PCP-laced joint, " he explains, "you have to look at the floor to see where your feet are. A few more hits and you dissociate from the environment. When a person drives under the influence of PCP, LSD or other hallucinogens, he may stop in the middle of a freeway to look at his map. Everything else going on him is not part of his experience—so why should he care about other cars?"
B
The changes in a person' s perception, mood, and thinking during cocaine intoxication are particularly retevant to driving skills.
The most dramatic effects of cocaine with respect to driving are on vision. Cocaine may cause a higher sensitivity to light, halos around objects, and difficulty focusing. Users have also reported blurred vision, glare problems, and hallucinations, particularly "snow lights"—weak flashes or movements of light in the peripheral field of vision, which tend to make drivers swerve toward or away from the lights. Some users have also reported auditory hallucinations(e. g. ring bells)and old factory hallucinations(e. g. smell of smoke or gasoline).
Many users say that cocaine actually improves their driving ability, which is not surprising because the drug induces euphoria and feelings of increased mental and physical abilities. Such self-reports must be accepted with caution , however, since these effects of cocaine are short-lived and are often followed by fatigue and lassitude.
Cocaine can also heighten irritability, excitability, and startle response. Users have reported that sudden sounds, such as horns or sirens, have caused them severe anxiety coupled with rapid steering or braking reactions, e-ven when the source of the sound was not in the immediate vicinity of their vehicles. Suspiciousness, distrust, and paranoia—other reactions to cocaine—have prompted users to flee in their cars or drive evasively.
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