Một máy bay đang bay theo phương ngang ở độ cao 8 km so với mặt đất, với tốc độ 720 km/h. Người phi công phải thả bom từ xa cách mục tiêu (theo phương ngang) bao nhiêu để quả bom rơi trúng mục tiêu? Lấy g = 9,8 m/s².

Cho hai tập hợp $A$ và $B$ khác rỗng thỏa mãn: $A \subset B$. Mệnh đề nào sau đây sai?

Choose the word(s) OPPOSITE in meaning to the underlined word(s).

Many women prefer to use cosmetics to enhance their beauty and make them look younger.

Khi đọc bản vẽ chi tiết, người ta đọc yêu cầu kĩ thuật để biết:

Khi ô tô đang chạy với vận tốc 10 m/s trên đoạn đường thẳng thì người lái xe tăng ga và ô tô chuyển động nhanh dần đều. Sau 20 s, ô tô đạt vận tốc 14 m/s. Quãng đường mà ô tô đã đi được sau $40s$ kể từ lúc bắt đầu tăng ga và tốc độ trung bình trên quãng đường đó lần lượt là

Đâu là ý nghĩa sinh học của hiện tượng thụ tinh kép ở thực vật hạt kín?

Men răng là lớp ngoài cùng của răng, được coi là chất cứng nhất trong cơ thể người. Chính nhờ lớp men này mà răng của chúng ta có thể chịu được những lực nhai nghiền lớn. Một trong những yếu tố quan trọng tạo nên độ cứng chắc của men răng chính là các khoáng chất tự nhiên, trong đó phải kể đến khoáng chất Ca₅(PO₄)₃(OH). Khi trong khoang miệng có sự lên men tạo acid, hoặc quá trình ăn uống có loại thức ăn có tính acid, nhóm OH⁻ trong khoáng chất sẽ phản ứng, lâu dần làm mất đi khoáng chất, men răng trở nên yếu đi, dễ bị vi khuẩn tấn công và gây sâu răng. Để thế vào vị trí của nhóm OH⁻ đó, ion nào sau đây được bổ sung vào thành phần của kem đánh răng?

1. Do you find yourself yawning all day at school? You probably need more sleep. However, it is not just how much sleep you get that is important. What you do before bedtime also has a huge effect on how you feel the next day. If you spend time chatting to someone on social media, or reading a book on your e- reader, you are not alone.

2. All devices' screens give out a large amount of blue light, which affects the body's production of the sleep hormone, melatonin, which can change your sleep patterns. So it is not just getting to sleep that becomes hard, but the quality of your sleep also suffers. The result is that you can wake up several times during the night, and have difficulty getting up in the morning.

3. Sleep is food for the brain, so not sleeping well can be a severe problem for anyone, especially for teenagers, because their brains are still developing. When you do not sleep well, it can be difficult to concentrate at school, which makes it harder to learn and get good grades. It can also affect your mood, making you feel sad or anxious.   

4. So, it is clear you should not use your phone before you go to sleep. Why not leave it in another room? Nothing on social media is so important that it cannot wait a few hours! You should rediscover paper books and enjoy feeling tired and sleepy before bedtime rather than wondering why your best friend has not liked your photo! How will you wake up? You do not have to use the alarm on your phone. Go and buy yourself an old-fashioned alarm clock! The negative effects that screen time is having on sleep have been in the news a lot recently, so manufacturers of smartphones and tablets have added a feature to the mobile devices that can help reduce these. Most new phones have a night-time setting that changes the colour of the screen so that it gives out less blue light. If you really cannot avoid going onto social media at bedtime, think about turning on this setting on your phone.

What does the word it in paragraph 4 refer to?

Mặt đứng của ngôi nhà:

Sự kiện nào đã “phá vỡ trận tuyến” của chủ nghĩa tư bản, làm cho nó không còn là hệ thống hoàn chỉnh, duy nhất trên toàn thế giới?

Read the following passage about the Pathways from Today's Actions to Tomorrow's World 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.

As we stand at the crossroads of environmental decision-making, the actions we take today will shape our world in 2050. Scientists warn that we're skating on thin ice with current consumption patterns and carbon emissions. Global temperatures could rise by 2-4 degrees Celsius unless significant changes occur within the next decade. Many countries have pledged to achieve carbon neutrality by 2050, but these promises require immediate implementation. Individual choices in transportation, energy usage, and consumption can collectively influence whether future generations inherit a sustainable planet or face severe climate consequences.

[I] Technological innovation represents our greatest hope for addressing environmental challenges by 2050. [II] Renewable energy sources like solar and wind are becoming increasingly affordable, potentially replacing fossil fuels entirely within thirty years. [III] Electric vehicles may dominate transportation networks, while vertical farming could transform food production in urban areas. [IV] However, these technological solutions must be developed and deployed equitably to avoid creating new disparities between wealthy and developing nations.

Social structures will undergo dramatic transformation by 2050 as demographic shifts reshape communities worldwide. Aging populations in developed countries will necessitate new approaches to healthcare, retirement, and social support systems. Meanwhile, climate migration may force millions to relocate from vulnerable coastal and drought-prone regions. Education systems must evolve to prepare our students for jobs that don't yet exist, emphasizing their adaptability and lifelong learning. Cities will need to become more resilient, incorporating green spaces and sustainable infrastructure to support growing populations.

Economic models must fundamentally change by 2050 to balance prosperity with environmental responsibility. The traditional focus on continuous growth may shift toward measuring success through wellbeing indicators rather than GDP alone. Circular economy principles will likely replace linear production models, with products designed for reuse and recycling. Resource-sharing platforms may become more prevalent, reducing individual consumption while maintaining living standards. Companies implementing genuinely sustainable practices will thrive, while those clinging to environmentally harmful methods may disappear entirely. The transition presents both challenges and opportunities for businesses willing to embrace innovation and sustainability.

Which of the following can be inferred from the passage?

Cho các số tự nhiên $a, \, b, \, c$ thỏa mãn cả hai điều kiện $20\lt a\lt b$ và $24>c>b$. Tìm $c$.

Read the following passage about Renewable energy sources 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.

          [I] Renewable energy sources, such as solar, wind, and hydroelectric power, have gained global popularity as a sustainable alternative to fossil fuels. [II] Unlike coal and oil, renewable energy generates electricity without releasing harmful emissions, making it a cleaner option for the environment (Jacobson et al., 2017). [III] However, despite the advantages of renewable energy, there are still notable challenges that need to be addressed for it to fully replace traditional energy sources (Ell Abban et al., 2014). [IV]

          One major advantage of renewable energy is its sustainability. Renewable resources, unlike fossil fuels, are naturally replenished and do not deplete over time. For instance, solar power harnesses energy from sunlight, which is virtually endless. In addition, renewable energy contributes to reducing greenhouse gas emissions, which helps combat climate change. Many countries are increasingly investing in renewable technologies to decrease their carbon footprint and meet international climate goals.

          However, renewable energy has certain limitations. One significant issue is its intermittent nature; for example, solar and wind power depend on weather conditions, making it difficult to generate a consistent power supply. This variability can disrupt the energy grid, which relies on a steady supply of electricity to meet demand. Another challenge is the high initial cost of setting up renewable energy facilities. Although prices have decreased in recent years, installing solar panels or wind turbines still requires substantial upfront investment (IRENA, 2019).

          Despite these challenges, advancements in technology are gradually making renewable energy more efficient and accessible. Improved energy storage systems, such as batteries, allow excess power generated during favourable conditions to be stored and used later, ensuring a more reliable energy supply. As technology and infrastructure improve, renewable energy may eventually.

Which of the following is TRUE according to the passage?

Chọn một từ/ cụm từ mà nghĩa của nó KHÔNG cùng nhóm với các từ/ cụm từ còn lại.

Đọc đoạn trích sau và trả lời câu hỏi:

Pierre đứng ở giữa phòng, suy nghĩ về những gì vừa diễn ra. Anh cảm thấy một nỗi buồn sâu sắc và mơ hồ, như thể có điều gì đó đang chờ đợi anh ở phía trước, nhưng anh không thể biết chắc nó là gì. Trong khi đó, Natasha đứng ở góc phòng, nhìn anh với đôi mắt đầy thắc mắc, nhưng Pierre không hề hay biết về những cảm xúc của cô.

(L.Tôn-xtôi, Chiến tranh và hoà bình, NXB Văn học, 2010)

Xác định điểm nhìn trần thuật được sử dụng trong đoạn trích trên.

Cho dãy số \(\left( {{u_n}} \right)\), biết rằng \({u_n} = \frac{n}{{{2^n} - 1}}\). Ba số hạng đầu tiên của dãy số là?

a. Ahmed: That's because the ice in the Arctic is melting.

b. Kenji: That's terrible for the polar bears and other animals that live there.

c. Kenji: Why is the ice melting?

d. Ahmed: Because of global warming. The Earth is getting warmer, so the ice is turning to water.

e. Kenji: I saw a picture of a polar bear on a small piece of ice.

Trường hợp nào sau đây ta không có một tụ điện?