Một đèn phát ra bức xạ có tần số f = 10¹⁴Hz. Bức xạ này thuộc vùng bức xạ

Vecto $\overrightarrow{k}(0;0;1)$ là vectơ pháp tuyến của mặt phẳng nào sau đây?

Sâu hại biến thái hoàn toàn phát triển qua mấy giai đoạn?

Nhận định nào dưới đây không phải là biểu hiện của quá trình toàn cầu hóa kinh tế?

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 30 to 34.

    A new study highlights the health benefits of natural spaces in urban areas. Researchers found that people (30) _______ with plenty of green space, such as parks, have lower stress levels. (31) ____________ showed higher stress levels than men in the same situation.

    The research proved that why (32) _______. There is good evidence from the UK and elsewhere suggests that green spaces lead to lower blood pressure, better mental health, and (33)____________or dying from heart disease.

    Studies also indicate that spending time in natural environments improves mental and physical health, reducing the burden on healthcare systems. Consequently, (34)__________and green areas as part of  their efforts to enhance public well-being.

Điểm \(A(2;3)\) thuộc miền nghiệm của hệ bpt nào?

Phiên mã ngược là quá trình tổng hợp DNA dựa trên khuôn mẫu RNA. Quá trình này được xúc tác bởi một loại enzyme đặc biệt gọi là enzyme phiên mã ngược (RT: reverse transcriptase). Enzyme này có cả hoạt tính DNA polymerase và hoạt tính RNase H. Cũng giống như DNA polymerase trong quá trình tái bản DNA, enzyme phiên mã ngược đòi hỏi phải có primer (mồi) đặc biệt để tổng hợp nên DNA mới.

Enzyme phiên mã ngược được phát hiện lần đầu tiên ở retrovirus. Sau khi các retrovirus đi vào tế bào vật chủ, genome của RNA của nó sẽ được phiên mã ngược thành DNA sợi đôi, rồi tích hợp vào DNA của vật chủ.

Thành phần nào dưới đây không tham gia vào quá trình phiên mã ngược?

Điều kiện xác định của phương trình \(\sqrt{4-2 x}=\frac{x+1}{x^{3}-3 x+2}\) là

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions.

Taking Home the World Cup

Standing just 36 centimeters tall, the FIFA World Cup Trophy symbolizes the pinnacle of football achievement.  Every four years, teams worldwide compete for it, but no one ever takes the trophy home. Made of 18-carat gold, the original trophy remains under FIFA's protection, with winners receiving only a replica. This measure safeguards it from theft, as the trophy has been stolen twice in its history.

The original trophy was made by a French sculptor, Abel LaFleur, and was called the “Jules Rimet Cup,” in honor of the founder of the World Cup tournament. Sometime during the first three World Cup events (1930, 1934, and 1938), the name changed to simply the “World Cup.” Then during World War II, not much was seen or heard of the trophy. It was being kept hidden in a shoe box under the bed of Dr. Ottorino Barassi, the Italian vice-president of FIFA, to prevent it from falling into the hands of the Nazi army. In 1966, the Cup was stolen during a public showing of the trophy prior to the World Cup tournament in England. Luckily, it was found a short time later, none the worse for wear, in a trash container by a little dog named Pickles. Four years later, Brazil earned permanent possession of the original trophy by winning its third World Cup title. Unfortunately, the trophy was stolen a second time in 1983 and was never recovered. The Brazilian Football Association had to have a duplicate trophy made.

(I) After the first trophy became the possession of Brazil’s football association, a new World Cup Trophy for FIFA was designed by an Italian artist, Silvio Gazzaniga, in 1974. (II) This trophy cannot be won outright, but remains in the possession of FIFA, and rest assured they are watching it very closely. Today, World Cup winners are awarded a replica of the trophy that is gold-plated, rather than solid gold like the real one. (III) Gazzaniga’s World Cup trophy weighs almost five kilograms. (IV) Its base contains two layers of a semi-precious stone called malachite, and has room for seventeen small plaques bearing the names of the winning teams---enough space to honor all the World Cup champions up to the year 2038. After that, a new trophy will have to be made.

According to the passage, which of the following statements is TRUE?

Phương án nào sau đây là đúng khi nói về thông tin và dữ liệu?

Phương án nào sau đây nêu đúng kết quả thập phân của phép tính 0101 × 01011?

(Gợi ý: 47₁₀ = 0101111₂; 55₁₀ = 00110111₂; 36₁₀ = 0100100₂; 49₁₀ = 0110001₂)

Boron là nguyên tố có nhiều tác dụng đối với cơ thể người như: làm lành vết thương, điều hoà nội tiết sinh dục, chống viêm khớp,... Do ngọn lửa cháy có màu lục đặc biệt nên boron vô định hình được dùng làm pháo hoa. Boron có hai đồng vị là ¹⁰B và ¹¹B, nguyên tử khối trung bình là 10,81. Tính phần trăm số nguyên tử mỗi đồng vị của boron.

1. % ¹⁰B = %.

Một loại vi khuẩn sau mỗi phút số lượng tăng gấp ba biết rằng sau \(4\) phút người ta đếm được có \(121\,500\) con. Sau bao nhiêu phút thì có được \(3\,280\,500\) con?

Read of the following leaflet and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 7 to 12.

Diversity Unleashed: Your Passport to 2025

Join us for a global (7)_________ of cultures, ideas, and innovation!

Some travelers prefer adventure holidays, while (8)_________ enjoy relaxing at resorts. We offer both!

Our skilled teachers will help you (9)_________ basic language skills before your cultural exchange program. (10)_________ cultural differences, we explore unique perspectives through interactive workshops.

Experience culinary (11)_________ from six continents prepared by master chefs. (12)_________ of opportunities are available for networking with global professionals.

Diversity Unleashed 2025 - Discover, Connect, Transform!

Book your spot today:

Early Bird Registration: Until March 31, 2025

Regular Registration: April 1 - June 30, 2025

Website: www.diversity2025.com

Email: info@diversity2025.com

Phone: (555) 123-4567

Read the following passage about education in Nepal and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions from 31 to 40. 

A few years ago, amid a record drought, scientists noticed something odd. A few of California’s giant sequoias inside Sequoia and Kings Canyon National Parks were dying in ways no one had ever documented – from the top down. When researchers climbed into the canopies, they discovered that beetles had bored into a few branches. By 2019, at least 38 of the trees had died – not a large number, but "concerning because we’ve never observed this before,” says Christy Brigham, the park’s chief of resource management.

Scientists had assumed that stately sequoias, with their bug-repelling tannins, were immune to dangerous pests. Worried experts are investigating whether some mix of increased drought and wildfire, both worsened by climate change, have now made even sequoias susceptible to deadly insect invasions.

If so, these ancient sentinels would be just the latest example of a trend experts are documenting around the world: Trees in forests are dying at increasingly high rates—especially the bigger, older trees. According to a study in the journal Science, the death rate is making forests younger, threatening biodiversity, eliminating important plant and animal habitat, and reducing forests’ ability to store excess carbon dioxide generated by our consumption of fossil fuels. [A]

There is no single direct cause. Decades of logging and land clearing play a role, scientists say. But increasing temperatures and rising carbon dioxide from the burning of fossil fuels have significantly magnified most other causes of tree death. Scientists are documenting longer and harsher droughts, more severe outbreaks of insects and disease, and increasingly catastrophic wildfires.

With 60,000 known tree species on Earth, those shifts are playing out differently across the planet. In central Europe, for instance, “You don’t have to look for dead trees,” says Henrik Hartmann, with Germany's Max Planck Institute for Biogeochemistry. “They’re everywhere.” In one recent year, following a week of excessive heat, hundreds of thousands of beech trees dropped their leaves. Even in colder regions, “You get a couple of hot years and the forests are suffering,” says Hartmann. “There are individual species that are being driven beyond the threshold of what they can handle.” [B]

Just last year, massive fires marched through a dry Australia, smoldered across 7.4 million acres in northern Siberia, and focused the world’s attention on blazes in the Amazon.

The consequences of all these changes around the world are still being assessed. The first national look at tree mortality in Israel showed vast stretches disappearing, thanks largely to scorching heat and wildfires. [C] In a country largely blanketed by stone and sand, forests mean a great deal. Trees support nests for eagles and habitat for wolves and jackals. They hold soil with their roots. [D]

“We’re dealing with a very tough situation. It’s a race to the unknown,” says Tamir Klein at the Weizmann Institute of Science.

In which space (marked A, B, C and D in the passage) will the following sentence fit?

Without them, plants that normally rise in trees’ shadows are suddenly exposed to higher temperatures and bright light.