Khi nói về đột biến số lượng NST, kết luận nào sau đây không đúng?

Cho phương trình $7^{2x+1}-{8.7}^x+1=0$ có hai nghiệm $x_1,x_2\left(x_1<x_2\right)$. Khi đó giá trị $\frac{x_2}{x_1}$?

Phương án nào sau đây là điều xảy ra nếu KHÔNG tuân thủ quy trình lắp đặt?

Một trong những hạn chế của phần mềm nguồn mở là gì?

Đặc điểm của miễn dịch thứ phát là gì?

Việc chấp hành đúng quy định của pháp luật về thống kê và công khai ngân sách là thuộc tính nào của ngân sách nhà nước?

Một hãng dược phẩm dùng những chiếc lọ bằng nhựa có dạng hình trụ để đựng thuốBiết rằng mỗi lọ có thể tích là \(16\pi \) cm\({{}^{3}}\) và bề dày không đáng kể. Tính bán kính đáy \(R\), đơn vị cm của lọ để tốn ít nguyên liệu sản xuất lọ nhất (kể cả nắp lọ).

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.

Which of the following is probably the author’s advice for a better bedtime?

Hiến pháp có vị trí như thế nào trong hệ thống pháp luật Việt Nam?

Công nghệ nào không phải là công nghệ ứng dụng để xử lý chất thải?

Với ruồi giấm, alen B quy định thân xám trội hoàn toàn so với alen b quy định thân đen. Alen V quy định cánh dài trội hoàn toàn so với alen v quy định cánh cụt. Khi cho hai dòng thuần chủng thân xám, cánh dài lai với thân đen, cánh cụt, thu được F₁ đồng tính. Cho F₁ giao phối với nhau, đời F₂ thu được có 10% cá thể thân xám, cánh cụt. Hãy xác định tần số hoán vị gen của F₁.

Mark the letter A, B, C, or D on your answer sheet to indicate the sentence(s) that best complete(s) each of the following exchanges.

Lucky: “________________________”

David: “Oh, about 25 minutes usually.”

Cho một vật dao động điều hòa có phương trình dao động x = 5cos(2πt + ) cm. Xác định gia tốc của vật khi x = 3 cm

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 1 to 5.

The process of sorting through the various holidays on offer and determining which is the best for you is inevitably complex and individual personality traits will determine the eventual decision. Some people undertake a Other process of extensive problem solving, in which information is sought about a series of products, (1) _________ . Other consumers with no patience to explore a variety of choices (2) _________ , for the sake of their convenience rather than trying to guarantee that they buy the best possible product. This is known as limited problem solving.

Many consumers engage in routinised response behaviour, in which choices change relatively little over time. (3) _________ . Also, some holidaymakers who have been content with a particular company or destination in the past may opt for the same experience again. 

Finally, some consumers will buy on impulse. (4) _________ .  It is, in fact, a pattern of behaviour that is becoming increasingly prevalent -- to the dismay of the operators, who then have less scope for forward planning and reduced opportunities to gain from investing deposits in the short term. (5) _________ , where 'distressed stock' needs to be cleared at short notice and this can be stimulated by late availability offers particularly.

(Adapted from The business of tourism)

Choose the best answer for number 5:

Nguyên tử oxygen có 8 proton, vậy điện tích hạt nhân của nguyên tử này tính theo đơn vị culong là

Read the following passage about the impact of social media on mental health and mark the letter A, B, C, or D on your answer sheet to indicate the best answer to each of the following questions

[I] In recent years, social media platforms have become a central part of daily life, offering users countless ways to connect, share, and communicate. [II] While these platforms offer many advantages, experts have noted rising concerns about their effects on mental health, particularly among young people (Smith & Anderson, 2018). [III] Studies reveal that excessive social media use can contribute to feelings of anxiety, depression, and loneliness, despite its intention to promote connection and social interaction (Twenge & Campbell, 2019). [IV]

A primary reason for these mental health concerns is the tendency for social media users to compare themselves to others. Platforms like Instagram and Facebook often highlight idealized lifestyles, leading users to feel inadequate about their own lives. Additionally, the constant notifications and messages contribute to a "fear of missing out," or FOMO, which keeps individuals in a cycle of checking their phones, often reducing the quality of sleep and overall well-being.

There is also a growing body of research suggesting a link between social media use and decreased attention spans. When users frequently switch between apps and notifications, their ability to focus for extended periods may diminish (Rosen, 2019). This shift in attention can interfere with productivity, especially in academic and professional settings, where sustained focus is essential.

Addressing these challenges requires a multi-faceted approach. Some mental health professionals suggest limiting screen time and setting boundaries, such as "device-free" hours before bedtime. Others recommend engaging in offline activities, like reading or exercising, to reduce dependence on social media and build healthier habits. According to psychologists, such strategies can bu mental resilience and allow for more meaningful, balanced relationships (Robinson & Smith, 2020).

The phrase "fear of missing out" in paragraph 2 could be best replaced by ____.

Một viên đạn đang bay với vận tốc 10m/s thì nổ thành hai mảnh. Mảnh thứ nhất, chiếm 60% khối lượng của viên đạn và tiếp tục bay theo hướng cũ với vận tốc 25m/s. Tốc độ và hướng chuyển động của mảnh thứ hai là

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

Global Issues: Gender Equality and Women’s Empowerment

Gender equality means that men and women have equal power and equal opportunities for financial independence, education, and personal development. Women's empowerment is a critical aspect of achieving gender equality. It includes increasing a woman's sense of self-worth, her decision-making power, her access to opportunities and resources, her power and control over her own life inside and outside the home, and her ability to effect change. Yet gender issues are not focused on women alone, but on the relationship between men and women in society. The actions and attitudes of men and boys play an essential role in achieving gender equality.

Education is a key area of focus. Although the world is making progress in achieving gender parity in education, girls still make up a higher percentage of out-of-school children than boys. Approximately one quarter of girls in the developing world do not attend school. Typically, families with limited means who cannot afford costs such as school fees, uniforms, and supplies for all of their children will prioritize education for their sons. Families may also rely on girls' labor for household chores, carrying water, and childcare, leaving limited time for schooling. But prioritizing girls' education provides perhaps the single highest return on investment in the developing world. An educated girl is more likely to postpone marriage, raise a smaller family, have healthier children, and send her own children to school. She has more opportunities to earn an income and to participate in political processes, and she is less likely to become infected with HIV.

Women's health and safety is another important area. HIV/AIDS is becoming an increasingly impactful issue for women. This can be related to women having fewer opportunities for health education, unequal power in sexual partnership, or as a result of gender-based violence. Maternal health is also an issue of specific concern. In many countries, women have limited access to prenatal and infant care, and are more likely to experience complications during pregnancy and childbirth. This is a critical concern in countries where girls marry and have children before they are ready; often well before the age of 18. Quality maternal health care can provide an important entry point for information and services that empower mothers as informed decision-makers concerning their own health and the health of their children.

A final area of focus in attaining gender equality is women's economic and political empowerment. Though women comprise more than 50% of the world's population, they only own 1% of the world's wealth. Throughout the world, women and girls perform long hours of unpaid domestic work. In some places, women still lack rights to own land or to inherit property, obtain access to credit, earn income, or to move up in their workplace, free from job discrimination. At all levels, including at home and in the public arena, women are widely underrepresented as decision-makers. In legislatures around the world, women are outnumbered 4 to 1, yet women's political participation is crucial for achieving gender equality and genuine democracy.

According to the passage, why is maternal infant and child health important to a community?