Một máy tạo rung được sử dụng để tạo ra sóng trên dây.

Cho khoảng cách từ ròng rọc đến máy tạo rung là 90cm. Bước sóng của sóng trên là:

Biết \(\lim _{x \rightarrow 3} \frac{x^{2}+b x+c}{x-3}=8(b, c \in \mathbb{R})\). Giá trị \(P=b+c\) bằng

Nội dung nào dưới đây nằm trong chế độ chính trị của nước Cộng hoà xã hội chủ nghĩa Việt Nam?

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 from 31 to 40.

[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 enhance mental resilience and allow for more meaningful, balanced relationships (Robinson & Smith, 2020).

The word "enhance" in paragraph 4 is OPPOSITE in meaning to ____.

"Mua được hàng hóa rẻ hơn, chất lượng tốt hơn". Đây là sự cạnh tranh giữa những chủ thể nào?

Read the following passage about Singapore Science Centre 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.

The Singapore Science Centre, situated on a sprawling six-hectare site in Jurong, offers a captivating way to explore the wonders of science and technology. Here, visitors can engage with interactive exhibits that make learning both fun and memorable. Clap your hands, and colorful bulbs will light up; spin a wheel, and it will activate a fan. This engaging environment sparks curiosity and fuels the imagination of both children and adults.

The centre boasts more than four hundred exhibits across various fascinating topics, including solar radiation, communication, electronics, mathematics, nuclear energy, and evolution. These exhibits are designed to foster interest in science and technology among the public, making the centre a hub for educational exploration.

Notably, it is the first science centre to be established in Southeast Asia. Officially opened in 1977, the centre now welcomes an average of 1,200 visitors daily, highlighting its enduring popularity and educational value.

The exhibits are thoughtfully arranged across four main galleries: the Lobby, Physical Sciences, Life Sciences, and Aviation. To ensure a fresh and engaging experience, the exhibits are renewed annually, encouraging repeat visits. Visitors are encouraged to interact with the exhibits, as opposed to traditional “hands-off” policies in most museums. Here, pushing buttons, turning cranks, or pedaling mechanisms are all part of the fun and learning experience.

The Discovery Centre, added in 1985, is specially designed for children aged three to twelve, providing an exciting space for young minds to explore and experiment. Most recently, a stone-age exhibit was introduced, showcasing extinct animals and early human life, offering insights into prehistoric times.

With its interactive displays and immersive environment, the Singapore Science Centre continues to inspire a love for science and discovery, making it an unforgettable destination for learners of all ages.

The word its in paragraph 5 refers to______.

Hệ thống những quy tắc xử sự mang tính bắt buộc chung do Nhà nước ban hành và được bảo đảm thực hiện bằng quyền lực nhà nước là nội dung của khái niệm nào sau đây?

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.

Dear Kim,

a. If media shows only one type of people, children will not understand our big world.

b. Since we are friends from different countries, we know that sharing stories is important for the future.

c. When we see different faces on TV, we learn about new friends and places.

d. Although I am young, I think TV shows should show people from many countries.

e. Because you work at a TV station, can you make shows with people who look different?

Your friend,

LK

Bệnh do điều kiện ngoại cảnh bất lợi:

Đại biểu Hội đồng nhân dân có những trách nhiệm gì với cử tri?

Ngoại lực có nguồn gốc từ đâu?

Giá trị lớn nhất của \(F(x;y) = 5x - 3y\), với điều kiện \(\left\{ \begin{array}{l}x \ge 0\\0 \le y \le 5\\x + y - 2 \ge 0\\3x - y \le 6\end{array} \right.\) 

Read the following passage about urbanisation and mark the letter A, B, C, or D on your answer sheet to indicate the best answer to each of the following questions.

URBANISATION: A GROWING PHENOMENON

     Urbanisation is the process through which cities grow, and higher populations begin to inhabit urban areas. This phenomenon has accelerated significantly over the past few decades due to various factors. One of the primary drivers is the search for better employment opportunities. In rural areas, job prospects are often limited to agriculture and small-scale industries, which might not provide sufficient income. Consequently, people migrate to cities seeking better livelihoods and living standards.

     Additionally, urban areas offer more advanced educational facilities and healthcare services compared to rural regions. Many families move to cities to provide their children with higher-quality education and greater future opportunities. Access to hospitals and specialized medical services also attracts people to urban centers, especially in countries where rural healthcare is underdeveloped.

     However, rapid urbanisation brings about several challenges. Overcrowding in cities can lead to inadequate housing, strained infrastructure, and increased pollution. The expansion of urban areas often results in the loss of green spaces and agricultural land, impacting food production and the environment. Governments and city planners must address these issues to ensure sustainable urban growth.

     Despite these challenges, urbanisation has several positive aspects. Cities are often cultural melting pots, where diverse groups of people interact, leading to vibrant communities and innovation. The concentration of resources and talents in urban areas can drive economic growth and technological advancements.

In which paragraph does the writer mention the impact of urbanisation on the environment?

Cho bảng số liệu dân số trung bình phân theo thành thị, nông thôn ở nước ta giai đoạn 2010 - 2020:

Nhận xét nào sau đây đúng với bảng số liệu trên?

Điện trường là:

Mối quan hệ cung - cầu có vai trò như thế nào đối với chủ thể sản xuất kinh doanh?

Ở loài ngô, bộ nhiễm sắc thể lưỡng bội là 2n = 20. Theo lý thuyết, số lượng nhiễm sắc thể có trong mỗi tế bào ở kì sau của quá trình nguyên phân là?

Đâu là ý đúng: Điều nào không đúng với vai trò của quan hệ cạnh tranh?