Cho tập hợp $A = \left\{ {1\,;\,2\,;\,3\,;\,4\,;\,x\,;\,y} \right\}$.
Xét các mệnh đề sau đây:
$\left( I \right)$: “$3 \in A$”.
$\left( II \right)$: “$\left\{ {3\,;\,4} \right\} \in A$”.
$\left( III \right)$: “$\left\{ {x\,;\,3\,;\,y} \right\} \in A$”.
Trong các mệnh đề sau, mệnh đề nào đúng?
Câu hỏi liên quan
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).
The word "enhance" in paragraph 4 is OPPOSITE in meaning to ____.
chọn đúng hoặc sai với mỗi ý a), b), c), d)
Hình bên biểu diễn sự thay đổi độ phóng xạ của một mẫu chất phóng xạ \({\beta ^ - }\)theo thời gian.
Đến thời hạn, người vay có nghĩa vụ và trách nhiệm phải hoàn trả cả vốn gốc và lãi vô điều kiện là nói đến đặc điểm nào sau đây của tín dụng?
Tìm giá trị nhỏ nhất của biết thức \(F=x+y\) trên miền xác định bởi hệ \(\left\{ \begin{align} x\ge 0 \\ 5x-4y\le 10 \\ 4x+5y\le 10 \\ \end{align} \right.\). (làm tròn kết quả đến chữ số thập phân thứ nhất).
Read the following passage 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] A newborn baby can see, hear and feel. By the age of five, a child can talk, ride a bike and invent imaginary friends. How does this development happen? [II]We don't understand the way language, thinking and planning develop very well. [III]Now scientists are using new technology to ‘see’ into children's brains. And they are discovering new information about the way a baby's brain develops. [IV]
A study in 2010 showed that children who were afforded more focus often gained an edge in IQ. The brain of a newborn infant contains nearly a hundred billion neurons. This number is comparable to that of an adult's brain. As they mature, an infant assimilates information through the sensory modalities of sight, hearing, smell, taste, and touch. This information fosters intricate connections between different regions of the brain. By the age of three, there are approximately a hundred trillion synaptic connections.
One experiment looked at images of babies' brains while they were listening to different sounds. The sounds were in different sequences. For example, one sequence was mu-ba-ba. This is the pattern ‘A-B-B’. Another sequence was mu-ba-ge. This is the pattern ‘A-B-C’. The images showed that the part of the brain responsible for speech was more active during ‘A-B-B’ patterns. This shows that babies can tell the difference between different patterns. This experiment is interesting because sequences of words are important to grammar and meaning. Compare two sentences with the same words in a different order: ‘John killed the bear’ is very different from ‘The bear killed John.’ So babies are starting to learn grammatical rules from the beginning of life.
Researchers also know that babies need to hear a lot of language in order to understand grammar rules. But there is a big difference between listening to television, audiobooks or the internet, and interacting with people. One study compared two groups of nine-month-old American babies. One group watched videos of Mandarin Chinese sounds. In the other group, people spoke the same sounds to the babies. The test results showed that the second group could recognize different sounds, however, the first group learned nothing. The scientist, Patricia Kuhl, said this result was very surprising. It suggests that social experience is essential to successful brain development in babies.
The word “recognize” in paragraph 4 is OPPOSITE in meaning to:
Đâu không phải là tác phẩm của Chu Văn Sơn?
Cơ chế của thị trường có các ưu điểm gì?
Cho biết đâu là địa chỉ URL tìm kiếm?
Điểm công nghiệp có vai trò nào?
Hai phương pháp cơ bản trong nghiên cứu lịch sử là
Nguyên lí máy Turing ra được công bố năm nào?
Đọc đoạn thơ sau và trả lời câu hỏi:
Mẹ vá nỗi buồn thành manh áo niềm vui
khoác lên người con đêm lạnh giá
dọn dẹp lối đi sình lầy rơm rạ
để gót chân son không lấm bẩn bụi bùn
Mẹ khom lưng mòn mỏi trên đồng
cho dáng hình con vươn cao đứng thẳng
đêm thức trắng đêm
ngày đội mưa cõng nắng
con trẻ an lành bên giấc ngủ no say
Đường con đi rộng thênh thang tương lai
đường của mẹ gập ghềnh bao khó nhọc
con mải miết kiếm tìm hạnh phúc
đâu hay rằng hạnh phúc ở sau lưng
(Nguyễn Minh Ngọc Hà, Mẹ, NXB Hội nhà văn, 2024)
Đoạn thơ trên sử dụng bao nhiêu từ láy?
Có hai lực đồng quy và . Gọi α αlà góc hợp bởi và và . Nếu thì:
Đạo đức trong kinh doanh có vai trò như thế nào?
Căn cứ thứ ba để lựa chọn nghề nghiệp trong lĩnh vực công nghệ là:
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!
(39) _______
Chính phủ của nước Cộng hòa xã hội chủ nghĩa Việt Nam hoạt động thông qua hình thức nào?
Đọc đoạn trích sau và trả lời câu hỏi:
(1) Nhựa nóng mười năm nhân dân máu đổ
(2) Tây Bắc ơi, người là mẹ của hồn thơ
(3) Mười năm chiến tranh, vàng ta đau trong lửa
(4) Nay trở về, ta lấy lại vàng ta.
(Tiếng hát con tàu, Chế Lan Viên)
Câu thơ nào trong đoạn trích trên được lấy ý từ câu ca dao?
Ý nào dưới đây là sai khi bàn về vấn đề cạnh tranh trong nền kinh tế thị trường?
Read the following leaflet and mark the letter A, B, C, or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 7 to 12. (1,5 points)
HEALTHY EATING MADE EASY!
Eating well is essential for a balanced life. Here are some tips to get you started:
- Include plenty of fruits and vegetables in your diet. You can find (7) _____ options at your local market.
- When cooking, try to (8) _____ unhealthy fats and sugar. Use fresh ingredients instead!
- Remember to drink enough water, (9) _______ it is crucial for your health and helps keep you energized.
- If you feel hungry between meals, reach for (10) _____ snacks like nuts or yogurt instead of chips.
- It’s important to have moderate food (11) _____. Overeating can lead to health (12) ______.
- Lastly, enjoy your meals with family or friends to make eating a joyful experience.
