Cho hàm số $y=\frac{3x-1}{x-3}$. Gọi giá trị lớn nhất là M, giá trị nhỏ nhất mà m trên $\left[0;2\right]$. Khi đó m + M có giá trị là?

Nội dung nào sau đây thể hiện cách phân loại thị trường?

Sau đây là một số ý kiến về khả năng của máy tính trong các lĩnh vực.

Giá trị của giới hạn \(\mathop {\lim }\limits_{x \to 3} \sqrt {\frac{{9{x^2} - x}}{{\left( {2x - 1} \right)\left( {{x^4} - 3} \right)}}} \) là

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)

Which of the following is probably the author’s advice for a better bedtime?

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.

Which of the following best summarizes paragraph 4?

Nội dung nào sau đây không phải là vai trò của lịch sử và văn hóa đối với sự phát triển ngành du lịch?

Các lĩnh vực Vật lí mà em đã được học ở cấp trung học cơ sở?

Để lập được kế hoạch tài chính cá nhân và thực hiện thành công cần thực hiện bao nhiêu bước cơ bản?

Read the passage below and choose A, B, C or D to fill in each blank.

In Part Three of the Speaking Section you work together with a partner. You have to do a single task which usually lasts about 3 minutes. One possible task is “problem solving”, which means you have to look at some visual information and then discuss the problem with your partner. You may be shown photos, drawings, diagrams, maps, plans, advertisements or computer graphics and it  is essential that everyone (631)___________ them carefully. If necessary, check you know exactly (632) ________________ the examiner to repeat the (633) __________ or make them clearer.

While you are doing the task, the examiner will probably say very little and you should ask your partner questions and (634)  ___________ suggestions if he or she is not saying much. If either of you have any real difficulties, the examiner may decide to step in and help. Normally, however, you find plenty to say, which helps the assessor to give you a fair mark. (635) ____________in doing the task by competing with your partner, which includes taking turns in giving opinions and replying appropriately, although in the end it may be possible to “agree to disagree”.

Liên hợp quốc ra đời trong thời kì hình thành trật tự thế giới mới

Choose the word(s) OPPOSITE in meaning to the underlined word(s).
I think we cannot purchase this device this time as it costs an arm and a leg.

Choose the word that differs from the rest in the position of the main stress: dangerous, impressive, adventure, develop

Một đoàn tàu rời ga chuyển động nhanh dần, sau 20 giây tàu đạt tốc độ 36 km/h. Tính gia tốc của tàu.

Cho phản ứng hoá học sau: 3Cu + 8HNO₃ → 3Cu(NO₃)₂ + 2NO + 4H₂O. Vai trò của HNO₃ trong phản ứng hoá học này là

Có mấy vai trò của chăn nuôi đối với đời sống kinh tế - xã hội?

Cho \(F(x) = 3x^2 +1\) và \(G(x)=4x^2+2x\) lần lượt là nguyên hàm của \(f(x)\) và \(g(x)\). Xét \(H (x)\) là một nguyên hàm của hàm số \(h(x) = f(x)g(x)\). Phương án nào dưới đây đúng?

Với Chính sách kinh tế mới, nhân dân Xô viết đã hoàn thành như thế nào?

Yếu tố nào làm nên sức sống và sức hấp dẫn của thơ hai-cư?

a. Tom: It's when we lose different kinds of plants and animals forever.

b. Carlos: My teacher told us about biodiversity loss today. It sounds scary.

c. Tom: Yes, often because we destroy their homes or hunt too many of them.

d. Carlos: Like when an animal becomes extinct?

e. Carlos: We need to protect all the different kinds of life on our planet.