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2026年4月托福机经套卷(第1套)Read an Academic Passage5 道题

Quantum Dots

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Quantum Dots Quantum dots are tiny semiconductor particles with unique optical properties, making them valuable in display technology. When exposed to light, these nanoparticles emit bright, pure colors that can be finely tuned by varying their size. This allows for more vibrant and accurate colors in screens, surpassing traditional display technologies. Their application in displays has revolutionized the consumer electronics industry. For example, quantum dot-enhanced televisions offer a broader color spectrum and energy conservation compared to conventional light-emitting diode (LED) displays because they require less backlighting. Environmental benefits are another advantage. Traditional displays often use harmful heavy metals like cadmium and lead. Quantum dots can be made from less toxic materials, and researchers are working on cadmium-free quantum dots to further reduce environmental impact. The manufacture of quantum dots requires extreme precision. As a result, challenges remain in scaling up production. However, this is a worthwhile endeavor because quantum dots potentially have many applications outside of electronics, such as in biological research. Their small size and bright emission are ideal for tagging and tracking molecules in living organisms. This allows for long-term observation of dynamic biological processes.
Question 1查看单题
The color of quantum dots can be controlled by changing
Atheir size after exposure to light
Bthe direction in which they are displayed
Cthe amount of light they are exposed to
Dthe color of the light they are exposed to
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正确答案:A
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Question 2查看单题
What makes quantum dot technology in televisions efficient?
AThe vibrancy of the colors
BThe reduced need for backlighting
CThe larger color spectrum
DThe size of the particles
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正确答案:B
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Question 3查看单题
What is identified as an environmental benefit of quantum dots?
AThe ability to make cadmium more pure
BThe ability to remove lead from living organisms
CLimiting environmental impacts to small areas
DLess use of some poisonous substances
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正确答案:D
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Question 4查看单题
Why does the passage state that the "manufacture of quantum dots requires extreme precision"?
ATo imply that quantum dots' environmental impact might increase
BTo praise the hard work of quantum dot manufacturers
CTo challenge the claim that using quantum dots is worthwhile
DTo explain why the production of quantum dots is difficult to increase
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正确答案:D
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Question 5查看单题
How can biologists use quantum dots?
AFor studying very small living organisms
BFor observing the movement of molecules
CFor including electronic tools in research
DFor making some biological processes more dynamic
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正确答案:B