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.
Which claim from the passage best describes the benefits of nanotechnology?
- A. Scientists can develop novel technologies and products.
- B. Nanotechnology is defined as the understanding and control of matter at dimensions of roughly 1 to 100 nanometers.
- C. The different colors can be used in simple medical tests to indicate infection or disease.
- D. Unique properties of materials emerge.
Correct Answer: D
Rationale: The correct answer is D because the passage specifically states that at the nanoscale, unique properties of materials emerge, which is a key benefit of nanotechnology. Choice A talks about what scientists can do but does not directly describe the benefits mentioned in the passage. Choice B is the definition of nanotechnology and not a specific benefit. Choice C mentions the use of different colors in medical tests, which is a specific application rather than a general benefit of nanotechnology.
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The Moon has been worshipped by primitive peoples and has inspired humans to create everything from lunar calendars to love sonnets, but what do we really know about it? The most accepted theory about the origin of the Moon is that it was formed of the debris from a massive collision with the young Earth about 4.6 billion years ago. A huge body, perhaps the size of Mars, struck the Earth, throwing out an immense amount of debris that coalesced and cooled in orbit around the Earth.The development of Earth is inextricably linked to the Moon; the Moon's gravitational influence upon the Earth is the primary cause of ocean tides. In fact, the Moon has more than twice the effect upon the tides than does the Sun. The Moon makes one rotation and completes a revolution around the Earth every 27 days, 7 hours, and 43 minutes. This synchronous rotation is caused by an uneven distribution of mass in the Moon (essentially, it is heavier on one side than the other) and has allowed the Earth's gravity to keep one side of the Moon permanently facing Earth. It is an average distance from Earth of 384,403 km.The Moon has no atmosphere; without an atmosphere, the Moon has nothing to protect it from meteorite impacts, and thus the surface of the Moon is covered with impact craters, both large and small. The Moon also has no active tectonic or volcanic activity, so the erosive effects of atmospheric weathering, tectonic shifts, and volcanic upheavals that tend to erase and reform the Earth's surface features are not at work on the Moon. In fact, even tiny surface features such as the footprint left by an astronaut in the lunar soil are likely to last for millions of years, unless obliterated by a chance meteorite strike. The surface gravity of the Moon is about one-sixth that of the Earth's. Therefore, a man weighing 82 kilograms on Earth would only weigh 14 kilograms on the Moon.
Why does the author mention 'impact craters' in line 16?
- A. To explain the corrosive effects of atmospheric weathering
- B. To explain why the Moon has no plant life because of meteorites
- C. To show the result of the Moon not having an atmosphere
- D. To show the result of the Moon not having active tectonic or volcanic activity
Correct Answer: C
Rationale: The mention of impact craters in the text is to highlight the consequence of the Moon lacking an atmosphere. The absence of an atmosphere on the Moon leaves it vulnerable to meteorite impacts, resulting in the multitude of impact craters on its surface. Choice A is incorrect because the mention of impact craters is not related to atmospheric weathering but rather to the lack of an atmosphere. Choice B is incorrect as it misinterprets the reason for the absence of plant life on the Moon. Choice D is incorrect as the text explicitly states that the Moon lacks tectonic or volcanic activity, which is not the focus of the mention of impact craters.
Today, bicycles are so common that it's hard to believe they haven't always been around. But two hundred years ago, bicycles didn't even exist, and the first bicycle, invented in Germany in 1818, was nothing like our bicycles today. It was made of wood and didn't even have pedals. Since then, however, numerous innovations and improvements in design have made the bicycle one of the most popular means of recreation and transportation around the world.
In 1839, Kirkpatrick Macmillan, a Scottish blacksmith, dramatically improved upon the original bicycle design. Macmillan's machine had tires with iron rims to keep them from getting worn down. He also used foot-operated cranks like pedals, so his bicycle could be ridden at a quick pace. It didn't look much like a modern bicycle, though, because its back wheel was substantially larger than its front wheel.
In 1861, the French Michaux brothers took bicycle design a step further by introducing a metal frame, making bicycles stronger and lighter. They also used rubber tires, which provided better traction and allowed for a more comfortable ride.
Finally, in 1874, the first truly modern bicycle appeared on the scene, complete with solid rubber tires, ball bearings, and even a chain drive, which enabled the rider to pedal at a higher speed with less effort. Today bicycles are built, used, and enjoyed all over the world.
Why did Macmillan add iron rims to the tires of his bicycle?
- A. Increase the weight of the bicycle.
- B. Enhance the durability of the tires.
- C. Reduce the bumpiness of the ride.
- D. Decrease the level of fatigue during the ride.
Correct Answer: B
Rationale: Macmillan added iron rims to his bicycle tires to enhance their durability and make them last longer. This innovation aimed to prevent the tires from getting worn down quickly. Adding weight to the bicycle (Choice A) was not the purpose of adding iron rims. While adding iron rims could potentially reduce the bumpiness of the ride (Choice C) by providing more stability, the main objective was to improve tire longevity. Similarly, reducing the level of fatigue during the ride (Choice D) was not the primary reason for adding iron rims.
The Moon has been worshipped by primitive peoples and has inspired humans to create everything from lunar calendars to love sonnets, but what do we really know about it? The most accepted theory about the origin of the Moon is that it was formed of the debris from a massive collision with the young Earth about 4.6 billion years ago. A huge body, perhaps the size of Mars, struck the Earth, throwing out an immense amount of debris that coalesced and cooled in orbit around the Earth.The development of Earth is inextricably linked to the Moon; the Moon's gravitational influence upon the Earth is the primary cause of ocean tides. In fact, the Moon has more than twice the effect upon the tides than does the Sun. The Moon makes one rotation and completes a revolution around the Earth every 27 days, 7 hours, and 43 minutes. This synchronous rotation is caused by an uneven distribution of mass in the Moon (essentially, it is heavier on one side than the other) and has allowed the Earth's gravity to keep one side of the Moon permanently facing Earth. It is an average distance from Earth of 384,403 km.The Moon has no atmosphere; without an atmosphere, the Moon has nothing to protect it from meteorite impacts, and thus the surface of the Moon is covered with impact craters, both large and small. The Moon also has no active tectonic or volcanic activity, so the erosive effects of atmospheric weathering, tectonic shifts, and volcanic upheavals that tend to erase and reform the Earth's surface features are not at work on the Moon. In fact, even tiny surface features such as the footprint left by an astronaut in the lunar soil are likely to last for millions of years, unless obliterated by a chance meteorite strike. The surface gravity of the Moon is about one-sixth that of the Earth's. Therefore, a man weighing 82 kilograms on Earth would only weigh 14 kilograms on the Moon.
The word 'massive' in line 4 is closest in meaning to?
- A. Dense
- B. Impressive
- C. Huge
- D. Unavoidable
Correct Answer: C
Rationale: In the context of the passage, 'massive' is used to describe the size of the collision that formed the Moon, indicating something very large or huge. While 'dense' means closely compacted, 'impressive' means evoking admiration, 'huge' is the closest synonym to 'massive' in this context. 'Unavoidable' does not convey the same meaning as 'massive' in this sentence, making it incorrect.
The ability to see at a distance, in good light, does not diminish as a result of aging to the extent that other visual acuities do. Myopia, or nearsightedness, is more common to younger eyes, while presbyopia, or farsightedness, more commonly afflicts people as they age. The word presbyopia comes from Greek presbys, "old man," and opia, "eye," and names a condition in which, because the lens of the eye hardens slightly and loses elasticity as a person ages, one cannot as easily focus sharply on nearby objects. This condition leads to the familiar habit of lifting up one's glasses and bringing an object or reading material close to the face so that the eyes can more easily focus on it. The function of the lens is to accommodate different focal points so that sensory data can be correctly directed to the retina for interpretation into images by the brain. Corrective lenses, particularly bifocals or progressive lenses, adjust for the focal point aberration. In essence, they do the work that the eye can no longer do for itself
In the context of the passage, 'accommodate' means to
- A. Arrange lodging for
- B. Contain
- C. Make allowances for
- D. Excuse
Correct Answer: C
Rationale: In this context, 'accommodate' means to make allowances for different focal points of vision. The passage explains that the function of the lens is to adjust for different focal points so that sensory data can be correctly directed to the retina for interpretation into images by the brain. This aligns with the meaning of 'make allowances for' as it indicates adapting to or accommodating different needs or requirements. Choices A, B, and D are incorrect because in the context of the passage, 'accommodate' specifically refers to adjusting for different focal points of vision rather than arranging lodging, containing, or excusing.
VOICE:
What effect does your voice have on others? Does it persuade or irritate, attract or repel? One of the worst qualities is harshness. If you ever get the feeling that people are uncomfortable when you speak, it may be that your harsh tones are jarring their eardrums. your voice will sound unpleasant if it is shrill, grating, hard, piercing, brassy, to loud, or too nasal.
Harsh voice qualities usually come from too much tension in the throat and jaw. Tension tightens muscles and blocks the relaxed voice tones essential to a pleasing impression. Because tension occurs in higher pitched voices, women tend to have shriller voices than men, which usually makes them less desirable public speakers, newscasters, or political candidates.
The information presented is
- A. Balanced in its view of public speaking.
- B. Favoring people with low-pitched voices.
- C. Slanted against people with piercing voices.
- D. Neutral toward both high- and low-pitched voices.
Correct Answer: C
Rationale: The correct answer is C. The paragraph is biased against people with piercing or harsh voices, suggesting they are less desirable as public speakers, newscasters, or political candidates. The text explicitly mentions that harsh voice qualities, like being shrill, grating, hard, piercing, brassy, loud, or nasal, are undesirable and may make people uncomfortable when speaking. It also highlights that tension leading to harsh voice qualities is more common in higher-pitched voices, which are typically associated with women, making them less preferred for public speaking roles. Choices A, B, and D are incorrect because the text does not suggest a balanced view, favor low-pitched voices, or maintain neutrality towards both high- and low-pitched voices; instead, it emphasizes the negative impact of harsh and piercing voices.