Nokea
A nanometer is a billionth of a meter. A DNA molecule is 2 nanometers in diameter. Protein
molecules are about 10 nanometers in diameter. A human hair is 100,000 nanometers in diameter.
But what is a nanometer and how does it relate to technology? Nanotechnology is defined as the
understanding and control of matter at dimensions of roughly 1 to 100 nanometers, a scale at
which unique properties of materials emerge that can be used to develop novel technologies and
products. At the nanoscale, the physical, chemical, and biological properties of materials differ
from the properties of matter either at smaller scales, such as atoms, or at larger scales that we
use in everyday life such as millimeters or inches. Nanotechnology involves imaging, measuring,
modeling, and manipulating matter only a few nanometers in size. Gold nanoparticles are made
of the same material as in jewelry. But when light interacts with particles of gold, different colors
are reflected. The different colors can be used in simple medical tests to indicate infection or
disease. Metals such as copper become extremely rigid at the nanoscale, rather than bendable as
in copper wires seen in everyday use.
What is the major difference between matter at the nanoscale and matter at larger scales such as millimeters or inches?
- A. At the nanoscale, metals are bendable, and at larger scales, they are rigid.
- B. Matter has different and special characteristics at the nanoscale.
- C. At the nanoscale, matter has the same properties as matter at the atomic level.
- D. There is no difference.
Correct Answer: B
Rationale: The correct answer is B. Matter at the nanoscale exhibits unique properties that differ from those at larger scales, such as millimeters or inches. At the nanoscale, materials show novel characteristics that emerge due to their size, leading to different behaviors compared to the same materials at larger scales. This difference in behavior is a key aspect of nanotechnology, where understanding and controlling matter at the nanoscale allow for the development of innovative technologies and products.
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Electrocardiogram
The rhythmic sounds of "beep... beep... beep..." signify the measurement of the heart muscle's strength. This rhythmic signal varies from person to person and is recorded as an electrocardiogram (ECG). Within the body, a complex array of systemic neural responses generates electric currents that can be detected on the skin's surface. When a person is connected to an amplifier, these impulses are captured by an electrocardiograph. Most of the information gathered pertains to the heart, as it emits electric currents in waves. This "wave of excitation" propagates through the heart wall and is associated with electrical changes. The process occurs in three distinct phases. First, the "wave of excitation," accompanied by an electrical change, lasts for about 1 to 2 seconds following the contraction of the cardiac muscle. These electrical impulses are rhythmically discharged from the sinoatrial (SA) node, which acts as the heart's natural pacemaker, signaling the atrium to contract. The peak of the ECG reading is attributed to the atrioventricular (AV) node, which triggers the excitation of the ventricles. Finally, as the ventricles relax, any changes in the wave pattern can alert trained medical personnel to potential abnormalities within the heart.
What are the three phases of the "wave of excitation"?
- A. The discharge from the SA node, the peak ECG, and the excitement of the ventricle.
- B. The excitement of the ventricle, the relaxing of the ventricle, and the systemic neural response.
- C. The contraction of the atrium, the relaxation of the atrium, and the contraction of the ventricle.
- D. The excitation of the atrium, the excitement of the ventricle, and the relaxing of the ventricle.
Correct Answer: D
Rationale: The correct answer is D: 'The excitation of the atrium, the excitement of the ventricle, and the relaxing of the ventricle.' The 'wave of excitation' in the heart occurs in three main steps. Firstly, the excitation starts with the discharge from the SA node, indicating the contraction of the atrium. Secondly, the peak ECG reading is caused by the excitement of the ventricle. Lastly, the wave ends with the relaxing of the ventricle. Understanding these steps is crucial for interpreting electrocardiograms and identifying any abnormalities in the heart's electrical activity.
The Electoral College: The Electoral College has nothing to do with college and contains no students. The Electoral College consists of votes that each state acquires based on the number of representatives it has in Congress.
Each state has two electoral votes because each state has two senators. The remaining electoral votes are determined by the number of Congressmen, the number of which is based on the population of the state established by the Census taken each decade.
During the presidential election, most states cast all their electoral votes for the candidate who wins the popular vote in that particular state. It’s all very confusing, but the founding fathers knew what they were doing. By having and using the Electoral College, candidates campaign in every state, but just because they win the popular vote across the country
doesn’t mean they will always win the election. Case in point, in election 2000, Al Gore won
the popular vote across the country, but George W. Bush won more electoral votes. Therefore he became our 43rd president.
In the passage, the word 'cast' means to
- A. throw.
- B. turn and send in a particular direction.
- C. select actors for a play.
- D. give one's vote.
Correct Answer: D
Rationale: The correct answer is D: give one's vote. In the context of the passage, the word 'cast' is used to refer to the action of states giving their electoral votes to a candidate based on the popular vote. This interpretation aligns with the electoral process described in the passage, where states allocate their electoral votes to the winning candidate.
Choice A (throw) is incorrect because 'cast' in this context does not imply physically throwing something. Choice B (turn and send in a particular direction) is incorrect as it does not capture the voting action described in the passage. Choice C (select actors for a play) is incorrect as it does not relate to the electoral process or voting.
Therefore, the most appropriate interpretation of 'cast' in this passage is to give one's vote, making option D the correct answer.
Eating
Consumption of food is a universal necessity. Different
cultures have developed different methods to accomplish
the task. It is interesting to discover these differences and
learn new ways to do things.
European cultures developed cutlery (knives, forks, and
spoons) to enable people to efficiently eat their food.
Correct use of this toolĆ¢Ä‚¬Ä„¢s changes with the times-what was
polite in 1800 may not be considered proper manners
today.
China developed the chopstick as an efficient tool for
eating. Mastery of the use of chopsticks can be difficult
for the person not raised in the culture. The attempts of a
novice to use chopsticks can be very amusing to the
watcher, but frustrating for the hungry diner.
Space travel has created new challenges for consuming
food. Squeeze bottles and other unique packaging have
enabled space travelers to get their needed nutrition.
Chopsticks and forks do not work well in space.
Which statement from the article draws a conclusion?
- A. Mastery of the use of chopsticks can be difficult.
- B. It is interesting to discover new ways to do things.
- C. What was considered polite in the 1800s may not be considered proper manners today.
- D. Chopsticks and forks do not work well in space.
Correct Answer: B
Rationale: The correct answer is B. The statement 'It is interesting to discover new ways to do things' draws a conclusion by highlighting the intriguing aspect of exploring different methods of eating across cultures. While the other statements provide information and observations, this statement reflects on the overall fascination with learning about diverse food consumption practices.
The federal government regulates dietary supplements through the United States Food and Drug Administration (FDA). The regulations for dietary supplements are not the same as those for prescription or over-the-counter drugs. In general, the regulations for dietary supplements are less strict.
To begin with, a manufacturer does not have to prove the safety and effectiveness of a dietary supplement before it is marketed. A manufacturer is permitted to say that a dietary supplement addresses a nutrient deficiency, supports health, or is linked to a particular body function (such as immunity), if there is research to support the claim. Such a claim must be followed by the words Ć¢Ä‚¬Å“This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.Ć¢Ä‚¬Ā¯
Also, manufacturers are expected to follow certain good manufacturing practices (GMPs) to ensure that dietary supplements are processed consistently and meet quality standards.
Requirements for GMPs went into effect in 2008 for large manufacturers and are being phased in for small manufacturers through 2010.
Once a dietary supplement is on the market, the FDA monitors safety and product information, such as label claims and package inserts. If it finds a product to be unsafe, it can take action against the manufacturer and/or distributor and may issue a warning or require that the product be removed from the marketplace. The Federal Trade Commission (FTC) is responsible for regulating product advertising; it requires that all information be truthful and not misleading.
The federal government has taken legal action against a number of dietary supplement promoters or Web sites that promote or sell dietary supplements because they have made false or deceptive statements about their products or because marketed products have proven to be unsafe.
What is the meaning of the phrase phased in as it is used in the third paragraph?
- A. stunned into silence
- B. confused
- C. implemented in stages
- D. legalized
Correct Answer: C
Rationale: The phrase 'phased in' refers to a process that is implemented gradually or in stages over time. In the context of the paragraph, it means that the requirements for GMPs were gradually introduced for small manufacturers through 2010. This approach allows for a smoother transition and implementation of regulations without overwhelming all manufacturers at once. Therefore, the correct answer is C: 'implemented in stages.' Choices A, B, and D do not accurately reflect the meaning of 'phased in' in this context.
Cystic fibrosis is a disease that is passed down through families. It is caused by a defective gene
that makes the body produce abnormally thick and sticky fluid, called mucus. This mucus builds
up in the breathing passages of the lungs and in the pancreas. The buildup of mucus results in
life-threatening lung infections and serious digestion problems. The disease may also affect the
sweat glands and a man's reproductive system. Millions of Americans carry a CF gene, but do
not have symptoms. This is because a person with CF must inherit two defective genes, one from
each parent. About 1 in 29 Caucasian Americans have the CF gene. It is more common among
those of northern or central European descent. Most children with CF are diagnosed by age 2.
For a small number, the disease is not detected until age 18 or older. These children often have a
milder form of the disease.
What is the main purpose of the passage?
- A. To describe the causes of cystic fibrosis
- B. To explain how cystic fibrosis is passed down through families
- C. To overview the causes of CF and how it is carried
- D. To review why some Americans have CF, but others do not
Correct Answer: C
Rationale: The passage provides an overview of cystic fibrosis, explaining that it is a disease passed down through families due to a defective gene. It describes how the defective gene leads to the production of abnormally thick and sticky fluid, mucus, which affects the lungs, pancreas, sweat glands, and reproductive system. The passage also mentions the prevalence of the CF gene in certain populations and the age at which most children are diagnosed with the disease. Therefore, the main purpose of the passage is to give an overview of the causes of cystic fibrosis and how it is inherited, making choice C the correct answer.