Cho tứ diện \(A B C D\) có \(A C=A D=B C=B D=a\) và hai mặt phẳng \((A C D),(B C D)\) vuông góc với nhau. Tính độ dài cạnh \(C D\) sao cho hai mặt phẳng \((A B C),(A B D)\) vuông góc với nhau.

Cho S.ABCD có đáy là hình bình hành. Gọi M, N, Q lần lượt là trung điểm của BC, CD và SA. Thiết diện của mp(MNQ) với hình chóp là: 

Chủ thể sản xuất gồm các nhà đầu tư, sản xuất và hoạt động nào sau đây?

Read the following passage about human life expectancy 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. 

How long will a baby born today live? 100 years? 120 years? Scientists are studying genes that could mean long life for us all.

There are already many, many people who have passed the landmark age of 100. In fact, there are now so many healthy, elderly people that there’s a name for them: the wellderly. These are people over the age of eighty who have no major illnesses, such as high blood pressure, heart disease or diabetes.

There are many scientific studies of communities where healthy old age is typical. These include places like Calabria in southern Italy and the island of Okinawa in Japan. In Calabria, the small village of Molochio has about 2,000 inhabitants. And of these, there are at least eight people over a hundred years old. When researchers ask people like this the secret of their long life, the answer is almost always about food and is almost always the same: ‘I eat a lot of fruit and vegetables.’ ‘I eat a little bit of everything.’ ‘I neither smoke nor drink.’

In the past, scientists looked at things such as diet and lifestyle for an explanation of long life, but these days they are also looking at genetics. Researcher Eric Topol says that there must be genes that explain why people are protected from the effects of aging process. The new research into long life did scrutinize groups of people who have a genetic connection. One interesting group lives in Ecuador. In one area of the country there are a number of people with the same genetic condition. It’s called Laron syndrome. These people don’t grow very tall – just over one metre. But Laron syndrome also give them protection against cancer and diabetes. As a result, they live longer than other people in their families. Meanwhile, on the Hawaiian island of Oahu, there’s another group of long-lived men, Japanese-Americans. They have a similar gene to the Laron syndrome group.

Back in Calabria, researchers constructed the family trees of the 100-year-old people. They looked at family information from the 19th century to today. It is concluded that there are genetic factors that give health benefits to the men. This is a surprising result because generally in Europe, women live longer than men. So what really makes people live longer? It seems likely that it is an interaction of genes, the environment and probably a third factor – luck.

In which paragraph does the writer mention that most people talk about what to eat as the secret of their long life?

Cơ chế thị trường có những ưu điểm gì?

Chọn từ/ cụm từ thích hợp nhất để điền vào chỗ trống trong câu dưới đây.

______ chúng ta đều không chủ tâm tỏ ra ác ý trong giao tiếp,______ với kẻ thù thật sự.

Ý nào dưới đây phản ánh đúng đặc điểm trong văn hóa trong tiêu dùng của người Việt Nam?

Trong ngôn ngữ Python, tên nào sau đây là từ khoá?

Đọc đoạn trích và trả lời câu hỏi dưới đây.

Phiên âm:

Tẩu lộ tài tri tẩu lộ nan

Trùng san chi ngoại hựu trùng san

Trùng san đăng đáo cao phong hậu

Vạn lý dư đồ cố miện gian.

Dịch thơ:

Đi đường mới biết gian lao,

Núi cao rồi lại núi cao trập trùng;

Núi cao lên đến tận cùng,

Thu vào tầm mắt muôn trùng nước non.

(Hồ Chí Minh, Đi đường, in trong Nhật kí trong tù, Hồ Chí Minh toàn tập, NXB Chính trị Quốc gia, Hà Nội, 2002)

Có thể thay thế từ “gian lao” trong bản dịch bài thơ “Đi đường” bằng từ nào?

Điện trường là:

Nhờ lao động mà Người tối cổ đã làm được gì cho mình trên bước đường tiến hoá?

Kí hiệu của thể tích toàn phần là

Kết quả khi thực hiện chương trình sau?

>>> A = [1, 2, 3, 5]

>>> A.insert(2, 4)

>>> print(A)

Nhờ các dịch vụ kết nối nhà tuyển dụng và người lao động, thị trường việc làm giúp cho thị trường lao động nhanh chóng đạt đến trạng thái nào?

Cho biết kết quả của đoạn chương trình dưới đây?

a = 10

while a < 11:

print(a)

Phát biểu nào sau đây không đúng với dân cư và xã hội của Trung Quốc?

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).

Which of the following is TRUE according to the passage?

Mark the letter A, B, C or D 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

a. Sally:-  Have you been working on any new projects?

b. Sally: - Hi! Long time no see. How's everything going?

c. Janna: - Not really. I've been focusing on improving my skills before starting something new.

d. Janna: - Hey! I'm doing well, thanks. Just been really busy with work.

e. Sally: - That’s great to hear! I hope all your hard work pays off and leads to something amazing.