Đặt điện áp $u=220\sqrt{2}\cos (100\pi \mathrm{t}) \left(V\right)$ vào hai đầu của đoạn mạch thì cường độ dòng điện trong đoạn mạch là $i=2\sqrt{2}\cos (100\pi \mathrm{t}) \left(A\right)$. Công suất tiêu thụ của đoạn mạch là

Trong Một thời đại trong thi ca, Hoài Thanh đã nêu ra cách nhận diện tinh thần Thơ mới như thế nào?

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?"?

Mark the letter A, B, C or D on your answer sheet to indicate the best arrangement of utterances or sentences to make a meaningful exchange or text in each of the following questions from 13 to 17.

Hi Alex,

a. I appreciate the recommendation for the language app—it’s been so helpful for my French practice.

b. Thanks for the podcast you suggested last week; it was really inspiring to listen to successful language learners share their tips.

c. By the way, have you ever considered joining an online language exchange group? I think it could be fun to try together.

d. I’ve been trying to set aside more time for speaking practice, but it’s a bit challenging with my busy schedule.

e. Still, I’m motivated to improve my French, and I’ll let you know if I find other useful resources.

Write back soon,

Jordan

Nội dung nào dưới đây không phản ánh đúng về khái niệm “quyền cơ bản của công dân”?

Trong các hợp chất hữu cơ sau, hợp chất nào không được cấu tạo theo nguyên tắc đa phân?

Cuộc cách mạng nào dưới đây trở thành cốt lõi của cuộc cách mạng khoa học- công nghệ diễn ra từ những năm 70 của thế kỉ XX? 

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.

Mom: “It’s time to get up”

Son: “__________________”

Read the passage carefully.

1. It is estimated that about 40 per cent of the world's population use social media, and many of these billions of social media users look up to influencers to help them decide what to buy and what trends to follow. An influencer is a person who can influence the decisions of his or her followers because of his or her knowledge or special knowledge in a particular area, e.g. fashion, travel, or technology. Influencers are now seen by many companies as a direct way to customers' hearts. Brands are now asking powerful influencers to market their products. With some influencers charging up to $25,000 for one social media post, it is no surprise that more and more people are keen to become influencers, too. If you are one of them, then here are five tips on how to do it.

2. Choose your niche: What is the area that you know most about? What do you feel most excited talking about? Find the specific area that you are most interested in and develop it.

3. Choose your medium and write an interesting bio: Most influencers these days are bloggers and micro-bloggers. Decide which medium – such as your own online blog, Instagram or Snapchat – is the best way to connect with your followers and chat about your niche area. When you have done that, write an attention-grabbing bio that describes you and your speciality area in an interesting and unique way. Make sure that people who read your bio will want to follow you.

4. Post regularly and consistently: Many influencers post daily on their social media accounts. The more you post, the more likely people will follow you. Also, make sure that your posts are consistent and possibly follow a theme.

5. Tell an interesting story: Whether it is a photo or a comment that you are posting, use it to tell a story that will catch the attention of your followers and help them connectwith you.

6. Make sure people can easily find your content: Publicize your posts on a variety of social media by hashtags and catchy titles to make sure that they can be easily found. There is no point writing the most exciting blogposts or posting the most attractive photographs if no one is going to see them.

7. Most importantly, if you want to become a social media influencer, you need to have patience. Keep posting and your following will gradually increase. Good luck!

Choose an option (A, B, C, or D) that best answers each question.

What is the passage mainly about?

Vào năm 2020, chỉ số HDI của Cộng hòa Nam Phi đạt 0,727, được xếp vào nhóm có chỉ số HDI

Máy công tác nào chỉ là một bộ phận công tác?

Ý nào sau đây phản ánh đúng nguyên nhân khách quan dẫn đến tình trạng thất nghiệp?

Đường cong trong hình vẽ là đồ thị của hàm số nào dưới đây?

Đại lượng nào dưới đây là đại lượng vectơ?

Cho biết: Chức năng điều hòa hấp thụ các chất dinh dƣỡng và thải các sản phẩm trao đổi chất là?

Xét cân bằng: \(\mathrm{H}_{2}(\mathrm{g})+\mathrm{Cl}_{2}(\mathrm{g}) \leftrightarrow 2 \mathrm{HCl}(\mathrm{g})\) ở \(25^{\circ} \mathrm{C}\). Nếu nồng độ của \(\mathrm{H}_{2}\) tăng lên 4 lần, giữ nguyên nồng độ của \(\mathrm{Cl}_{2}\) thì nồng độ của HCl

Chức năng, nhiệm vụ của Quốc hội là gì?

Người ta cung cấp một nhiệt lượng 9500 J để một thanh kim loại có khối lượng 0,5 kg tăng nhiệt độ từ 25 ^oC lên 75 ^oC. Bỏ qua mọi hao phí khác. Kim loại này là

Trong các hoạt động kinh tế cơ bản không bao gồm hoạt động nào sau đây?

Các phát biểu nào dưới đây là đúng khi nói về ý nghĩa của hiện tượng ra mồ hôi của cơ thể người và động vật?