Dạng sóng của một tín hiệu âm có dạng như hình 2.11 dưới đây. Biết dao động kí đang chọn ở thang đo . Biết rằng một ô trong màn hình gọi là một div có giá trị 2,5 volt/div và 1,2 ms.

Hiệu số giữa tần số dao động của tín hiệu B và tần số của tín hiệu A là bao nhiêu Hz? (làm tròn đến chữ số hàng đơn vị)

Đáp án:

Một công ty sản xuất điện thoại di động bán trung bình 2000 chiếc mỗi tuần với giá 20 triệu đồng mỗi chiếc. Qua khảo sát thị trường, công ty nhận thấy rằng cứ mỗi lần giảm giá bán 1 triệu đồng, số lượng điện thoại bán ra sẽ tăng thêm 200 chiếc mỗi tuần. Tuy nhiên, nếu giảm giá bán quá nhiều, lợi nhuận biên từ mỗi chiếc điện thoại sẽ giảm xuống, với mỗi lần giảm giá thêm 1 triệu đồng, chi phí sản xuất cho mỗi chiếc điện thoại sẽ tăng thêm 500 nghìn đồng. Biết rằng chi phí ban đầu để sản xuất mỗi chiếc điện thoại là 10 triệu đồng, và chi phí cố định hàng tuần của công ty là 20,000 triệu đồng. Công ty nên đặt giá bán mỗi chiếc điện thoại ở mức nào để tối đa hóa lợi nhuận hàng tuần? (đơn vị triệu đồng, làm tròn đến hàng phần mười)

Một số vòi nước thường có hai tai vặn. Tác dụng chính của các tai vặn này là:

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.

In paragraph 1, what does the word them refer to?

Khi truy cập mạng, mọi người có thể bị kẻ xấu lợi dụng, ăn cắp thông tin hay không?

Read the following passage about beginning a lifelong journey 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 23 to 30.

Lifelong learning is the continuous pursuit of knowledge and skills throughout a person's life. In today's world, where technology is evolving rapidly, lifelong learning is essential for both personal growth and career development. But just how does one go about becoming a lifelong learner?

The first step in becoming a lifelong learner is to develop a growth mindset. This means believing that your abilities can be developed through hard work, dedication and commitment. Embrace challenges, view mistakes as opportunities to learn, and be open to new ideas and perspectives. Adopting a growth mindset will help you approach learning with a positive attitude and a desire to improve.

Setting achievable goals is also an important part of lifelong learning. Goals give direction and motivation to your learning journey. First, identify areas of interest and choose specific skills or knowledge that you want to develop. Second, break your goals down into smaller, more manageable tasks and track your progress. Finally, celebrate your accomplishments along the way to stay motivated.

People learn in different ways, so it's also essential that you find the methods that work best for you. You can do this by trying out a variety of different learning methods, such as reading, watching videos, attending lectures and engaging in hands-on practice. At the same time, you should also experiment with different learning tools and techniques until you find what works best for you. Becoming a lifelong learner is a continuous process that requires dedication and effort. Developing a growth mindset, setting achievable goals, and using a variety of learning methods are essential steps to becoming a successful lifelong learner. By embracing learning as a lifelong journey, you will continue to grow, develop new skills, and stay relevant in today's ever-changing world.

(Adapted from Bright)

The word rapidly in paragraph 1 is OPPOSITE in meaning to _____.

Vi điều khiển là mạch tích hợp có thể

Tại sao công nghệ số có thể giúp nâng cao tính minh bạch chuỗi cung ứng?

Hệ điều hành nào là OS thương mại tiêu biểu cho máy tính cá nhân?

Glycerol có công thức là \({{\text{C}}_{3}}{{\text{H}}_{5}}{{(\text{OH})}_{3}}\), được sử dụng để kiểm soát độ ẩm và giúp tăng cường độ kết dính trong kem dưỡng da. Nhận định đúng về glycerol là:

Cho hàm số \(f(x)=-x^{3}+m x^{2}-\left(m^{2}+m+1\right) x\). Với \(m\) là tham số thực.

Hàm số nghịch biến trên khoảng \((1; 3)\) khi và chỉ khi:

Hi Hong,

I hope you're doing well. You wanted to know about my family routines, so here they are.

a. Every Sunday morning, we go to the supermarket together.

b. I like listening to their stories about when they were young.

c. We buy food for the whole week and sometimes pick a treat for dessert.

d. Once every two weeks, we visit my grandparents. We have lunch together and then help them with gardening.

e. On Wednesday evenings, we cook a new recipe we've never tried before. It's exciting and sometimes very funny if the food looks strange.

These moments make me feel happy and connected. What routines do you enjoy with your family?

Write back soon.

Best,

Huong

Hoạt động nào dưới đây có thể gây nên mối lo ngại của xã hội về đạo đức sinh học?

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 = %.

Các bước nào dưới đây là đúng khi nói về tiến trình của phương pháp làm việc trong phòng thí nghiệm?

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

Why are we always pointing to Instagram as the cause of mental illness in our teenagers? It’s frustrating that abusive relationships, and the trauma they cause, are rarely mentioned in discussions about the prevalence of mental health problems in young people. Research by Women’s Aid and Cosmopolitan has found that a third of teenage girls have been in an abusive relationship. And, if that isn’t shocking enough, when the remaining two-thirds were asked further questions, it emerged that 64% of them had, in fact, experienced abusive behaviour – they just didn’t realise it was abuse.

Domestic abuse is normally associated with women cowering on the floor, as a violent husband waits to strike, or mothers covering up their black eyes with concealer before the school run. On the same day that the domestic abuse bill received its second reading in parliament, Age UK called for action to tackle domestic abuse of over-60s, whose needs it says are often overlooked by the law, policy and practice. The needs of teenagers in the heady throes of first love who are in emotionally abusive relationships also need to be recognised.

Common themes of such relationships include (though are not limited to) excessive jealousy, repeated criticism and sexual coercion. If your boyfriend or girlfriend is checking your phone, constantly asking to know your whereabouts, getting upset when you spend time away, turning up unannounced to surprise you, these are all examples of coercive control. If they never apologise in an argument and make everything your fault, tell you what you can and can’t wear, undermine you and/or publicly humiliate you under the guise of a “joke”, these again are common instances of controlling behaviour. Ditto, if they have a Jekyll/Hyde personality, make you feel like you are walking on eggshells even when things are seemingly going well, and threaten to hurt themselves if you leave. When it comes to sexual coercion and rape, examples include making you feel pressured to perform sexual acts you’re uncomfortable with, such as sending nude photos, having sex before you’re ready, being pressured to re-enact extreme sex from porn films or being told you don’t love them if you say no.

Often the victim in an abusive relationship can never quite put their finger on one thing, but the overwhelming feeling is of a general unease, feeling unsafe, defective, wrong, scared and as if you are going crazy. It’s your “yourselfness” that’s being consistently undermined, controlled and attacked by the person who claims to love you.

According to the passage, why have only a third of teenage girls been in an abusive relationship?