Hạt nhân của nguyên tử nào có số hạt neutron là 28?

Read the passage carefully

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.

(Adapted from Prepare)

Why does the author mention the sentence "How will you wake up?"?

Hình vẽ bên dưới mô tả sóng dừng trên dây có chiều dài ℓ . Bước sóng của sóng truyền trên dây là λ. Hệ thức đúng là

Cho phép tịnh tiến thep vector \(\overrightarrow{u}\left( 1;3 \right)\) biếnđường thẳng \(d:2x+y+1=0\) thành đường thẳng d’ có phương trình: 

Mark the letter A, B, C, or D on your answer sheet to indicate the correct option that best fits each of the numbered blanks from 18 to 22.

          The philosopher St. Augustine famously stated, "The world is a book, and those who do not travel read only a page." This notion aligns with the value of study-abroad programs, (18)_______ diverse cultures, languages, and perspectives. These programs are not merely about academic learning but are transformative journeys that often leave a profound impact on participants. Students describe these experiences as "rewarding" and even "life-changing," (19)________. Such programs not only enrich students academically but also prepare them to navigate a globalized world with empathy and understanding.

      A significant advantage of studying abroad lies in its ability to enhance experiential learning. Unlike traditional classroom instruction, firsthand encounters—such as observing art in its original context or engaging with local communities—can deepen one's understanding of a subject. As one student observed after viewing Michelangelo's David, (20)_________. Such moments sharpen one's senses, cultivate a sensitivity to beauty and pain, and foster a deeper awareness of the interconnectedness of human experiences.

     Moreover, studying abroad nurtures self-reflection, an essential aspect of personal growth. By documenting their experiences, students can analyze their values and beliefs (21)________. This reflective process not only enhances their capacity to adapt but also helps them better understand themselves and their aspirations. As educators recognize these multifaceted benefits, efforts continue to expand access to study-abroad opportunities, ensuring (22)________.

Nhận định nào sau đây đúng nhất khi nói về sự thay đổi mà mạng máy tính đối với phương thức học tập trong giáo dục?

Thực hiện Cấu hình tính năng sao lưu dữ liệu dự phòng để?

Phát biểu nào sau đây là sai?

Diện tích toàn phần của một hình lập phương bằng $294c{m}^2$. Tính thể tích khối lập phương đó?

Giá trị dương lớn nhất để hàm số \(y = \sqrt {5 - 4x - {x^2}} \) xác định là: 

Cho hàm số \(y=f(x)\) có đạo hàm \(\forall x \in \mathbb{R}\), hàm số \(f^{\prime}(x)=x^{3}+a x^{2}+b x+c\) có đồ thị như hình vẽ.

Số điểm cực trị của hàm số: \(y=f\left[f^{\prime}(x)\right]\) là:

Đâu là đặc điểm của ống rây?

Tìm số hạng chứa \(x^{31}\) trong khai triển \(\left(x+\frac{1}{x^{2}}\right)^{40}\).

Phương trình \(\frac{{2\sin x + \cos x + 1}}{{\sin x - 2\cos x + 3}} = a\) có nghiệm khi?

Choose the word or phrase among A, B, C or D that best fits the blank space following passage So you’re between the ages of thirteen and eighteen. What (36) _______ you happy? There have been lots of surveys about teenagers and happiness and they all come to different conclusions. Some surveys say that most young people are happiest (37) _________ they spend time with their family. Others say it’s when they’re (38) ________ friends. Some teenagers think that getting good marks at school and (39) _________ exams makes them happy and others feel that it’s having a boyfriend or girlfriend that improves their lives. The problem is that there isn’t just one thing that makes everyone happy. (40) __________ is something different for each of us, and what made us happy last week might not make us happy next week!

(40) _______

Số tập hợp con của tập hợp A có 5 phần tử là?

Đồ thị hàm số \(y = {6^{2x}}\) luôn đi qua điểm nào dưới đây?

Đâu là nội dung thể hiện đặc điểm của thị trường?

Một vật khối lượng 100 g rơi tự do được quãng đường 10 cm. Lấy g =10 m/s². Công của trọng lực tác dụng lên vật trên quãng đường nói trên là

Chiến thắng nào quyết định cuộc kháng chiến chống quân Xiêm giành thắng lợi?

a. Isabel: Yes, in many parts of the world, people don't have enough clean water.

b. Trang: We should be careful not to waste water when we brush our teeth or take a shower.

c. Trang: I learned that using too much water is a problem. It's called water scarcity.