It is most likely that you have never had diphtheria. You probably don’t even know anyone
who has suffered from this disease. In fact, you may not even
... [Show More] know what diphtheria is. Similarly, diseases like whooping cough, measles, mumps, and rubella may all be unfamiliar to you. In the nineteenth and early twentieth centuries, these illnesses struck hundreds of thousands of people in the United States each year, mostly children, and tens of thousands of people died. The names of these diseases were frightening household words. Today, they are all but forgotten. That change happened largely because of vaccines.
You probably have been vaccinated against diphtheria. You may even have been exposed to the bacterium that causes it, but the vaccine prepared your body to fight off the disease so quickly that you were unaware of the infection. Vaccines take advantage of your body’s natural ability to learn how to combat many disease-causing germs, or microbes. What’s more, your body remembers how to protect itself from the microbes it has encountered before. Collectively, the parts of your body that remember and repel microbes are called the immune system. Without the proper functioning of the immune system, the simplest illness—even the common cold—could quickly turn deadly.
On average, your immune system needs more than a week to learn how to fight off an unfamiliar microbe. Sometimes, that isn’t enough time. Strong microbes can spread through your body faster than the immune system can fend them off. Your body often gains the upper hand after a few weeks, but in the meantime you are sick. Certain microbes are so virulent that they can overwhelm or escape your natural defenses. In those situations, vaccines can make all the difference.
Traditional vaccines contain either parts of microbes or whole microbes that have been altered so that they don’t cause disease. When your immune system confronts these harmless versions of the germs, it quickly clears them from your body. In other words, vaccines trick your immune system in order to teach your body important lessons about how to defeat its opponents.
1. What is the main idea of the passage?
A. The nineteenth and early twentieth centuries were a dark period for medicine.
B. You have probably never had diphtheria.
C. Traditional vaccines contain altered microbes.
D. Vaccines help the immune system function properly.
2. Which statement is not a detail from the passage?
A. Vaccines contain microbe parts or altered microbes.
B. The immune system typically needs a week to learn how to fight a new disease.
C. The symptoms of disease do not emerge until the body has learned how to fight the microbe.
D. A hundred years ago, children were at the greatest risk of dying from now-treatable diseases.
3. What is the meaning of the word virulent as it is used in the third paragraph?
A. tiny
B. malicious
C. contagious
D. annoying
4. What is the author’s primary purpose in writing the essay?
A. to entertain
B. to persuade
C. to inform
D. to analyze
Questions 5 to 8 pertain to the following passage :
Foodborne illnesses are contracted by eating food or drinking beverages contaminated with bacteria, parasites, or viruses. Harmful chemicals can also cause foodborne illnesses if they have contaminated food during harvesting or processing. Foodborne illnesses can cause symptoms ranging from upset stomach to diarrhea, fever, vomiting, abdominal cramps, and dehydration. Most foodborne infections are undiagnosed and unreported, though the Centers for Disease Control and Prevention estimates that every year about 76 million people in the United States become ill from pathogens in food. About 5,000 of these people die.
Harmful bacteria are the most common cause of foodborne illness. Some bacteria may be present at the point of purchase. Raw foods are the most common source of foodborne illnesses because they are not sterile; examples include raw meat and poultry contaminated during slaughter. Seafood may become contaminated during harvest or processing. One in
10,000 eggs may be contaminated with Salmonella inside the shell. Produce, such as spinach, lettuce, tomatoes, sprouts, and melons, can become contaminated with Salmonella, Shigella, or Escherichia coli (E. coli). Contamination can occur during growing, harvesting, processing, storing, shipping, or final preparation. Sources of produce contamination vary, as these foods are grown in soil and can become contaminated during growth, processing, or distribution.
Contamination may also occur during food preparation in a restaurant or a home kitchen. The most common form of contamination from handled foods is the calicivirus, also called the Norwalk-like virus.
When food is cooked and left out for more than two hours at room temperature, bacteria can multiply quickly. Most bacteria don’t produce an odor or change in color or texture, so they can be impossible to detect. Freezing food slows or stops bacteria’s growth, but does not destroy the bacteria. The microbes can become reactivated when the food is thawed.
Refrigeration also can slow the growth of some bacteria. Thorough cooking is required to destroy the bacteria.
5. What is the subject of the passage?
A. foodborne illnesses
B. the dangers of uncooked food
C. bacteria
D. proper food preparation
6. Which statement is not a detail from the passage?
A. Every year, more than 70 million Americans contract some form of foodborne illness.
B. Once food is cooked, it cannot cause illness.
C. Refrigeration can slow the growth of some bacteria.
D. The most common form of contamination in handled foods is calicivirus.
7. What is the meaning of the word pathogens as it is used in the first paragraph?
A. diseases
B. vaccines
C. disease-causing substances
D. foods
8. What is the meaning of the word sterile as it is used in the second paragraph?
A. free of bacteria
B. healthy
C. delicious
D. impotent
Questions 9 to 12 pertain to the following passage:
There are a number of health problems related to bleeding in the esophagus and stomach. Stomach acid can cause inflammation and bleeding at the lower end of the esophagus. This condition, usually associated with the symptom of heartburn, is called esophagitis, or inflammation of the esophagus. Sometimes a muscle between the esophagus and stomach fails to close properly and allows the return of food and stomach juices into the esophagus, which can lead to esophagitis. In another unrelated condition, enlarged veins (varices) at the lower end of the esophagus rupture and bleed massively. Cirrhosis of the liver is the most common cause of esophageal varices. Esophageal bleeding can be caused by a tear in the lining of the esophagus (Mallory-Weiss syndrome). Mallory-Weiss syndrome usually results from vomiting, but may also be caused by increased pressure in the abdomen from coughing, hiatal hernia, or childbirth. Esophageal cancer can cause bleeding.
The stomach is a frequent site of bleeding. Infections with Helicobacter pylori (H. pylori), alcohol, aspirin, aspirin-containing medicines, and various other medicines (such as nonsteroidal anti- inflammatory drugs [NSAIDs]—particularly those used for arthritis) can cause stomach ulcers or infl [Show Less]