Antibiotics are administered to patients after surgery, even if no signs or symptoms of infection are present, in order to prevent this issue.

Antibiotics are drugs produced by certain microbes. Antibiotic substances are obtained from bacteria and fungi that live in the air, soil, and water. Most antibiotics are used by physicians to fight various diseases caused by harmful microbes. A few are used to treat certain cancers. Antibiotics are sometimes called" wonder drugs 'because they can cure many diseases that once were often fatal. The number of deaths that are caused by pneumonia and scarlet fever has declined drastically since people began using antibiotics.

2. There are more than 70 clinically useful antibiotics, Antibiotics fight pathogenic microbes and cancer cells by interfering with their normal cell processes. In most cases, this interference can occur in one of three ways: prevention of cell wall formation, disruption of the cell membrane, and disruption of chemical processes.

3. The contents of bacterial cells are enclosed in a membrane that is surrounded by a rigid wall that prevents the cells from splitting open. Penicillins and some other antibiotics destroy pathogenic microbes by hindering the formation of this wall. Human cells do not have nor need rigid cell walls and so are not damaged by these antibiotics.

4. Some antibiotics, including nystatin, disrupt the cell membrane of certain microbes. This membrane controls the movement of materials in and out of the cell. If the membrane is disrupted, vital nutrients may escape from the cell, or poisonous substances may enter and kill the cell. But the membranes of human cells are not affected because these antibiotics disrupt cell membranes that contain elements found only in microbial cells.

5. All cells produce proteins and nucleic acids, which are vital to the life of any organism. Some antibiotics fight disease by interfering with the chemical processes by which these substances are produced. For example, streptomycin prevent certain kinds of microbes from producing proteins, and rifampin interferes with the formation of nucleic acids. Human cells produce proteins and nucleic acids in much the same way that microbial cells do. But these processes differ enough so that some antibiotics interfere with chemical activities in microbial cells but not in human cells.

A. Autibiotics destroy pathosenic microbes by preventing the formation of the walls surrounding the membranes of the microbial cells that prevent the cells from split- ting open.

B. More than 70 clinically useful antibiotics have been in- vented to fight pathogenic microbes and cancer cells by interacting with their normal cell processes.

C. Human cells are not surrounded by a membrane

D. Some antibiotics disrupt the cell membrane of certain microbes, letting vital nutrients to escape form. the cell or poisonous substances to enter and kill the cell.

E. Nystatin is used to disrupt the wall surrounding the membrane.

F. Some antibiotics fight disease by interfering with chemical activities in microbial cells but not in human cells.

Paragraph 2______。

Antibiotics are drugs produced by certain microbes. Antibiotic substances are obtained from bacteria and fungi that live in the air, soil, and water. Most antibiotics are used by physicians to fight various diseases caused by harmful microbes. A few are used to treat certain cancers. Antibiotics are sometimes called" wonder drugs &39;because they can cure many diseases that once were often fatal. The number of deaths that are caused by pneumonia and scarlet fever has declined drastically since people began using antibiotics.

2. There are more than 70 clinically useful antibiotics, Antibiotics fight pathogenic microbes and cancer cells by interfering with their normal cell processes. In most cases, this interference can occur in one of three ways: prevention of cell wall formation, disruption of the cell membrane, and disruption of chemical processes.

3. The contents of bacterial cells are enclosed in a membrane that is surrounded by a rigid wall that prevents the cells from splitting open. Penicillins and some other antibiotics destroy pathogenic microbes by hindering the formation of this wall. Human cells do not have nor need rigid cell walls and so are not damaged by these antibiotics.

4. Some antibiotics, including nystatin, disrupt the cell membrane of certain microbes. This membrane controls the movement of materials in and out of the cell. If the membrane is disrupted, vital nutrients may escape from the cell, or poisonous substances may enter and kill the cell. But the membranes of human cells are not affected because these antibiotics disrupt cell membranes that contain elements found only in microbial cells.

5. All cells produce proteins and nucleic acids, which are vital to the life of any organism. Some antibiotics fight disease by interfering with the chemical processes by which these substances are produced.For example, streptomycin prevent certain kinds of microbes from producing proteins, and rifampin interferes with the formation of nucleic acids. Human cells produce proteins and nucleic acids in much the same way that microbial cells do. But these processes differ enough so that some antibiotics interfere with chemical activities in microbial cells but not in human cells.

Paragraph 2______。

A. Autibiotics destroy pathosenic microbes by preventing the formation of the walls surrounding the membranes of the microbial cells that prevent the cells from split- ting open. B. More than 70 clinically useful antibiotics have been in- vented to fight pathogenic microbes and cancer cells by interacting with their normal cell processes. C. Human cells are not surrounded by a membrane D. Some antibiotics disrupt the cell membrane of certain microbes, letting vital nutrients to escape form. the cell or poisonous substances to enter and kill the cell. E. Nystatin is used to disrupt the wall surrounding the membrane. F. Some antibiotics fight disease by interfering with chemical activities in microbial cells but not in human cells.

Paragraph 3______。

A. Autibiotics destroy pathosenic microbes by preventing the formation of the walls surrounding the membranes of the microbial cells that prevent the cells from split- ting open. B. More than 70 clinically useful antibiotics have been in- vented to fight pathogenic microbes and cancer cells by interacting with their normal cell processes. C. Human cells are not surrounded by a membrane D. Some antibiotics disrupt the cell membrane of certain microbes, letting vital nutrients to escape form. the cell or poisonous substances to enter and kill the cell. E. Nystatin is used to disrupt the wall surrounding the membrane. F. Some antibiotics fight disease by interfering with chemical activities in microbial cells but not in human cells.

Paragraph 4______。

A. Autibiotics destroy pathosenic microbes by preventing the formation of the walls surrounding the membranes of the microbial cells that prevent the cells from split- ting open. B. More than 70 clinically useful antibiotics have been in- vented to fight pathogenic microbes and cancer cells by interacting with their normal cell processes. C. Human cells are not surrounded by a membrane D. Some antibiotics disrupt the cell membrane of certain microbes, letting vital nutrients to escape form. the cell or poisonous substances to enter and kill the cell. E. Nystatin is used to disrupt the wall surrounding the membrane. F. Some antibiotics fight disease by interfering with chemical activities in microbial cells but not in human cells.

Paragraph 5______。

A. Autibiotics destroy pathosenic microbes by preventing the formation of the walls surrounding the membranes of the microbial cells that prevent the cells from split- ting open. B. More than 70 clinically useful antibiotics have been in- vented to fight pathogenic microbes and cancer cells by interacting with their normal cell processes. C. Human cells are not surrounded by a membrane D. Some antibiotics disrupt the cell membrane of certain microbes, letting vital nutrients to escape form. the cell or poisonous substances to enter and kill the cell. E. Nystatin is used to disrupt the wall surrounding the membrane. F. Some antibiotics fight disease by interfering with chemical activities in microbial cells but not in human cells.

Antibiotics cure diseases that used to be incurable, so they are sometimes called

A. antibiotics disrupt cell membranes that contain elements found only in microbial cells B. people began using antibiotics C. wonder drugs D. Penicillin may destroy normal cells of human beings E. vital to the life of any organism F. disruption of the cell membrane

The number of people who died from pneumonia and scarlet fever has declined since

A. antibiotics disrupt cell membranes that contain elements found only in microbial cells B. people began using antibiotics C. wonder drugs D. Penicillin may destroy normal cells of human beings E. vital to the life of any organism F. disruption of the cell membrane

The membranes of human cells can not be disrupted because ......

A. antibiotics disrupt cell membranes that contain elements found only in microbial cells B. people began using antibiotics C. wonder drugs D. Penicillin may destroy normal cells of human beings E. vital to the life of any organism F. disruption of the cell membrane

All cells produce proteins and nucleic acids which are

A. antibiotics disrupt cell membranes that contain elements found only in microbial cells B. people began using antibiotics C. wonder drugs D. Penicillin may destroy normal cells of human beings E. vital to the life of any organism F. disruption of the cell membrane

请帮忙给出每个问题的正确答案和分析，谢谢！

Antibiotic resistance doesn't just make pathogens(病原体) difficult to treat, It also makes them harder to track Traditionally, epidemiologists(流行病专家)following the paths of disease-causing microbes have identified their suspects by features of bacterial polysaccharide(多糖) coats, susceptibility to different antibiotics, or other schemes But these tracking techniques "are losing their relevance (相关性,实用性), "says Alexander Tomasz, a microbiologist at Rockefeller University in New York City. With the increase in drug resistance, a variety of resistant microbes can now wear the same coat or be resistant to the same drugs, making it harder and harder to keep tabs on individual strains (菌株).

Epidemiologists, therefore, are increasingly turning to more precise molecular typing techniques, such as DNA fingerprinting, to distinguish resistant strains.

DNA typing tools are, of course, not new. Indeed, some DNA-based methods, such as comparing plasmids (质体)(small rings of DNA outside the chromosomes 〈染色体〉), have been used by epidemiologists to track infections since the 1970s. but since plasmid DNA is transferred easily and often between different strains, that technique too has its limitations.

More recent techniques use restriction enzymes to cut apart entire bacterial chromosomes into strain-specific fragment patterns, Another method uses specific radiolabeled (放射标汇的) DNA probes, in a technique known as Southern hybridization(杂交), to test for the presence of a particular drug-resistance gene in a bacterial strain. "Such tools give epidemiologists, unprecedented resolving power for identifying reservoirs and transition routes of genes and pathogens, "says Tomasz. That has helped researchers track a number of drug-resistant clones as they travel vast distances.

Such tracking methods also "help us learn about the mechanism of resistance, "says CDC(疾病控制和预防中心) epidemiologist Robert Breiman. Resistance grows, he explains, either as one resistant organism spreads from one location to the next—as in the Brazilian MRSA(耐甲氧苯青素金黄色葡萄球菌)—or as different strains and even species of microbes share the genes responsible for drug resistance, as a series of studies of vancomycin(万古霉素) resistance recently demonstrated.

That knowledge also helps public health officials combat the spread. If resistance spreads "horizontally'as a microbe increases its range, Breiman says it's important to focus prevention efforts on minimizing person-to-person spread in hospitals and day-care centers. If, however, resistance genes are jumping between organisms, that suggests that overly aggressive antibiotic treatment is encouraging nonresistant bugs to acquire new genes. "In such cases, the focus needs to be on controlling anti-microbial use, "says Breiman. The hoped-for result: fewer infections to track.

Aspirin is one of the world's oldest pain remedies.

A．Right

B．Wrong

C．Not mentioned

Even with antibiotic treatment, death rate of cutaneous is still extremely high.

A．Y

B．N

C．NG

抗菌后效应(postantibiotic effect)

非共生起源学说(aeymbiotic theory)

根据以下材料，回答题

Biorobotics

Surgeons are being able to enter the eye to carry out operations——atleast in a virtual sense.

Techniques derived from virtual reality- the computer system that immerses operations in an artificial computer-generatedworld —— will allow surgeons to feel as if he could see the inside of， the eyeduring an operation， creating the illusion that they are actually there.

Researchers at the Biorobotics （生物机械人技术） Laboratory of McGill University in Montreal are building a robot， known as Micro SurgeryRobot-1 （MSR-I for short） ， that will perform. delicate operations under thecontrol of a human surgeon. The robot is specifically designed for performing eye surgery but could have other applications， such as the removal ofbrain tumors.

The system could also be used to allow surgeons and theirstudents to practice simulated surgery that feel like the real thing —— withoutthe real consequences for the patients.

During the operations， the surgeon manipulates a set of controls knownas the master. These are connected through a high-performance computer tothe robot. Both the master and the robot have two limbs. When the surgeonmoves the master"s limbs， the robot"s limbs move in exactly the same way， except that the movements can be sealed down as much as a thousandtimes. This will eliminate hand tremor and poor accuracy and thus reducethe damage to the eye that can occur with present microsurgery techniques.Each of the robot"s limbs has a minimum movement of one micrometer——more than one hundred times the precision of the human hand.

The computer also creates a three-dimensional robot"s eye view of theinside of the eye that the surgeon can see by wearing a virtual reality helmet （头盔） that has a small lens in front of each eye.

To provide the surgeon with such a realistic experience， MSR-I must beable to move rapidly，but this requires extremely fast computing. To handlethe computational demands of instant interaction， the McGill team is constructing its own parallel-processing computer. It is also studying areas such asmuscle mechanism， artificial intelligence and optics， and has already built another microrobot， MR-I， capable of manipulating a single living cell.

The so-called "virtual reality" mentioned in this passage refers to __________. 查看材料

A.operations conducted inside the eye

B.computer-created illusions that assist in operations

C.new applications of visual technology

D.new notions that help improve microsurgery

Most sore throats are caused by an infection which treatment with antibiotics cannot cure. But with simple remedies the patient normally gets better in 4 or 5 days. Sore throats are common. Most of the time the soreness is worse in the morning and improves as the day progresses.

Like colds, the vast majority of sore throats are caused by viral infections. This means most sore throats will NOT respond to antibiotics. Many people have a mild sore throat at the beginning of every cold. When the nose or sinuses become infected, drainage can run down the back of the throat and irritate it, especially at night. Or, the throat itself can be infected.

With a sore throat, sometimes the tonsils or surrounding parts of the throat are inflamed. Either way, removing the tonsils to try to prevent future sore throats is not recommended for most children.

Tonsillitis, however, usually starts with a sore throat which causes pain on swallowing. With children — and some adults — there may be a fever and the patient is obviously not feeling well. It may be possible to see white spots on the back of the throat. The neck may also swell, both of which are the normal response to infection. Sometimes a sore throat may occur with the common cold, and with influenza there may be dryness of the throat, pain on coughing and loss of voice.

TREATMENT:

Aspirin: To help relieve the pain on swallowing and (if there is one) the fever. Use aspirin tablets dissolved in water so that the patient can gargle before swallowing. Repeat the treatment every 4 hours.

Drink: Encourage the patient to drink plenty.

Food: Food should not be forced on a patient who does not want to eat.

Steam: If there is pain in the throat on coughing, breathing in steam may help. CHILDREN:

Young children, who may not be able to gargle, should be given aspirin dissolved in water every 4 hours in the right dose for their age.

At one year: A single junior aspirin.

At five years: Half an adult aspirin.

At eight years: One whole adult aspirin.

WHEN TO SEE THE DOCTOR.

If the sore throat is still getting worse after 2 days. If the patient complains of earache. If the patient's fever increases. If the patient or parent is very worried.

According to the passage, it would appear that most sore throats______.

A．require an immediate visit to a doctor

B．respond quickly to treatment with an antibiotic

C．rarely turn out to be serious illnesses

D．result in tonsillitis even when treated

Most people who develop Lyme disease, a tick-borne infection that's endemic in parts of the Northeast and Midwest, are easily cured by taking an antibiotic like doxycycline for a couple of weeks. But for years a debate has raged over what to do about patients whose symptoms (fatigue, mental confusion, joint pain) never seem to clear up. One small but vocal group of doctors and patient advocates believes that Lyme's corkscrew-shaped spirochetes have tunneled deep into their victims' bodies and can be eradicated only with intensive antibiotic treatment over many months. Another group believes, just as adamantly, that the bacteria are long gone, making further treatment with powerful antibiotics—which can lead to potentially fatal infections or blood clots—positively dangerous.

Now comes word of two studies in the New England Journal of Medicine that show that long-term antibiotic treatment is no better than a placebo for folks with chronic Lyme disease. Originally scheduled for publication in July, the research is part of a group of findings made public last week -just in time for the peak Lyme months of June and July. If confirmed by another major study that's looking at chronic Lyme and antibiotics from a slightly different perspective, the results would seem to settle the question once and for all.

Researchers from Boston, New Haven, Conn., and Valhalla, N. Y., followed 129 patients who had previously been treated for well-documented eases of Lyme disease. Sixty-four were given antibiotics directly into their veins for a month, followed by two months of oral antibiotics. The others received dummy medications. A third of the chronic Lyme patients got better while taking the antibiotics. But so did a third of those on the placebo. Indeed, the results were so similar that a monitoring board decided to cut the trials short rather than add more subjects to the test groups.

Unfortunately, the debate over chronic Lyme has become so heated that no one expects the controversy to go away. But both sides may take comfort in the other findings that were released by the New England Journal last week. After studying 482 subjects bitten by deer ticks in a part of New York with a lot of Lyme disease, researchers concluded that a singly 200-rug dose of doxycycline dramatically cut the risk of contracting the disease. That good news is tempered somewhat by the fact that 80% of patients who develop the infection don't remember ever being bitten by a tick. (The bugs inject an anesthetic into the skin to mask the pain and in their nymph stage are so small—about the size of a poppy seed--that they are easily overlooked.)

There's still plenty you can do to protect yourself in a Lyme-infested neighborhood: tuck your pants in your socks, spray DEET on your clothing, check yourself and your kids for ticks. And if you develop a spreading red rash—particularly if it's accompanied by joint pain, chills or confusion—make sure you see a doctor right away. The tick, as always, is to be vigilant without overreacting.

According to the passage, Lyme disease ______.

A．is one of the contagious diseases

B．is spread by a kind of tiny bugs

C．causes infection all over the body

D．develops against any painkillers

Most people who develop Lyme disease, a tick-borne infection that's endemic in parts of the Northeast and Midwest, are easily cured by taking an antibiotic like doxycycline for a couple of weeks. But for years a debate has raged over what to do about patients whose symptoms (fatigue, mental confusion, joint pain) never seem to clear up. One small but vocal group of doctors and patient advocates believes that Lyme's corkscrew-shaped spirochetes have tunneled deep into their victims' bodies and can be eradicated only with intensive antibiotic treatment over many months. Another group believes, just as adamantly, that the bacteria are long gone, making further treatment with powerful antibiotics—which can lead to potentially fatal infections or blood clots—positively dangerous.

Now comes word of two studies in the New England Journal of Medicine that show that long-term antibiotic treatment is no better than a placebo for folks with chronic Lyme disease. Originally scheduled for publication in July, the research is part of a group of findings made public last week—just in time for the peak Lyme months of June and July. If confirmed by another major study that's looking at chronic Lyme and antibiotics from a slightly different perspective, the results would seem to settle the question once and for all.

Researchers from Boston, New Haven, Conn., and Valhalla, N.Y., followed 129 patients who had previously been treated for well-documented cases of Lyme disease. Sixty-four were given antibiotics directly into their veins for a month, followed by two months of oral antibiotics. The others received dummy medications. A third of the chronic Lyme patients got better while taking the antibiotics. But so did a third of those on the placebo. Indeed, the results were so similar that a monitoring board decided to cut the trials short rather than add more subjects to the test groups.

Unfortunately, the debate over chronic Lyme has become so heated that no one expects the controversy to go away. But both sides may take comfort in the other findings that were released by the New England Journal last week. After studying 482 subjects bitten by deer ticks in a part of New York with a lot of Lyme disease, researchers concluded that a singly 200-mg dose of doxycycling dramatically cut the risk of contraction the disease. That good news is tempered somewhat by the fact that 80% of patients who develop the infection don't remember ever being bitten by a tick. (The bugs inject an anesthetic into the skin to mask the pain and in their nymph stage are so small—about the size of a poppy seed—that they are easily overlooked.)

There's still plenty you can do to protect yourself in a Lyme-infested neighborhood: tuck your pants in your socks, spray DEET on you clothing, check yourself and your kids for ticks. And if you develop a spreading red rash—particularly if it's accompanied by joint pain, chills or confusion—make sure you see a doctor right away. The trick, as always, is to be vigilant without overreacting.

According to the passage, Lyme disease ______.

A．is one of the contagious diseases

B．is spread by a kind of tiny bugs

C．causes infection all over the body

D．develops against any painkillers