Tập xác định của hàm số là 

Choose the best answer to fill in the blank.

A lot of people like to play their records as loudly as possible. The (1) ____ is that the rest of the family and the neighbors often complain (2) ____ don't like the music. One (3) ____ to this problem is to wear headphones, but headphones are usually uncomfortable.

An arm-chair which has a record-player built into it has just been (4) ____ by a British engineer, Stephen Court.

The armchair looks like an ordinary armchair with high back. However, each of the two sides of the chair has three loudspeakers inside to reproduce middle and high sounds. Low sounds are reproduced by a pair of loudspeakers in a hollow (5) ____ under the seat. Anyone who sits in the chair hears sounds coming from all around his/her head.

Because we cannot tell the exact (6) ____ from which low sounds come, it doesn't (7) ____ that they come from underneath or behind. It is the higher sounds coming from the sides of the chair that create a stereo effect.

These sounds travel only a few inches to reach the listener's ears. (8) ____, it takes only a little power to make the music sound very loud. Only a small amount of sound leaks out from behind the chair into the room to (9) ____ others. Most of the sound is (10) ____ by the listeners.

Choose the best answer for question 8:

Hình bên ghi nhận lại hiện tượng nguyên phân ở tế bào rễ hành tím khi xử lí với thuốc nhuộm carmin-acetic (45%) dưới kính hiển vi. Quan sát hình, hãy cho biết tế bào được xác định bởi mũi tên chỉ vào đang ở kì nào của nguyên phân?

Choose the word whose underlined part differs from the other three in pronunciation: cheap, child, chemist, chair

Phát biểu nào sau đây sai khi nói về python?

Read the following passage about addressing challenges and mark the letter A, B, C, or D to indicate the option that best fits each of the numbered blanks from 18 to 22.

Social issues are problems that affect a large number of people in society, often creating inequality and hardship. One of the most significant social issues today is poverty. (18) ______, such as food, shelter, and education. In many parts of the world, (19) ______, with families trapped in a cycle of deprivation. While poverty is a complex issue, it is often connected to factors like unemployment and lack of access to education. These factors make it hard for individuals to escape the cycle and improve their lives. To address poverty, governments and organizations must create sustainable policies that focus on education, healthcare, and employment opportunities.

Another pressing issue is gender inequality. In many countries, women still face discrimination in areas like employment and education, limiting their opportunities for personal and economic growth. Even in developed nations, women earn less than men for doing the same work. (20) ______, as people demand equal rights and opportunities for all genders. Moreover, gender inequality can also affect women’s health and safety, (21) ______.

Finally, environmental degradation, like pollution and climate change, is a growing global concern. Environmental damage, (22) ______, especially in poorer regions, often affects them the most. The increasing frequency of natural disasters, caused by climate change, is also putting immense pressure on vulnerable populations. Tackling these issues requires a collective effort from both individuals and governments. Only through cooperation and sustainable practices can we hope to create a more equitable and livable world for future generations.

Một con lắc lò xo gồm một lò xo có độ cứng 100 N/m gắn với vật nặng 100 g dao động điều hoà trong không khí dưới ngoại lực cưỡng bức . Để có thể xảy ra hiện tượng cộng hưởng, người ta thực hiện phương án nào sau đây?

Cho hàm số \(y=f(x)\) có bảng biến thiên như sau:

Giá trị lớn nhất của hàm số \(g(x)=f(\cos x-1)\) bằng:

Phát biểu nào không đúng với gió mùa?

Nhân tố khí hậu nào sau đây không thể hiện rõ sự khác biệt giữa phần lãnh thổ phía Bắc và phía Nam nước ta?

Read the following passage about managing change 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. 

Growing up in Athens, Greece, Lydia Borsi remembers feeling tested when she tried to deal with mental health issues. Borsi says she had been seeing a therapist for anxiety. But she notes that people in Greece do not openly discuss mental health issues, which also get little attention in general healthcare services. “It was a lot more secretive. And people thought that I was a lot more unique,” Borsi said.

That all changed in 2017 when she moved to the United States to study at the University of Rochester in Rochester, New York. “When I came here, I really liked that people were not afraid to speak up about mental health and say that it’s important,” she said. The university was very supportive of her needs and offered plenty of information. She also became involved with a school group called Active Minds that helps students deal with mental health issues. [A]

Then due to the spread of the novel coronavirus, the University of Rochester had to move all its classes and some of its mental health resources online. Luckily, Borsi was able to connect with a mental health expert outside the school, in the local community. [B]

But as many of her American friends returned home, Borsi was stuck. Greece had succeeded in limiting the spread of the virus within its borders, but flights there from the U.S. are barred until July. Also, the health crisis has put her plans to seek admission to medical school in Britain on hold. [C] And she is not alone.

[D] In April, Active Minds launched a survey of over 2,000 students at U.S. colleges and universities. The study found that over 80 percent of those asked said the coronavirus crisis had negatively affected their mental health. One in five said it has affected them severely.

Laura Horne, chief program officer at Active Minds, says the findings are especially troubling given that the crisis is only going to make it harder for colleges and universities to help these students. “Colleges and universities had to pivot rather quickly to respond to COVID-19 and figure out all facets of university life, including mental health services. Now they have to figure out how to communicate with students,” Horne said.

Frank Chen is a Houston, Texas-based psychiatrist who has worked with college-age young adults. He points out that individuals at that age are in an important stage of their mental development. And college can be a difficult experience for students with or without mental health issues, as they balance work, studies, and personal relationships. Adding a major world event, like the spread of the coronavirus, makes it very difficult to predict what the long-term psychological effects might be. “I don’t think that there’s another event in the history of the people who are alive now that can really measure up to this,” said Chen.

What does Frank Chen mean when he says, ‘I don’t think that there’s another event in the history of the people who are alive now that can really measure up to this’?

Ethanol có thể được sản xuất từ cellulose. Sử dụng lượng ethanol thu được từ 10 tấn mùn cưa (chứa 50% cellulose, phần còn lại là chất trơ) để pha chế ra ${\text{Vm}}^3$ xăng E5 (xăng chứa 5% ethanol về thể tích). Biết hiệu suất quá trình sản xuất ethanol từ cellulose là 60% và ethanol có khối lượng riêng là $0,789 \text{g} {\text{mL}}^{-1}$. Giá trị của V là

Cơ quan nào của nước ta thực hiện quyền lập hiến và quyền lập pháp?

Một dây đàn dài 0,6 m hai đầu cố định dao động với một bụng độc nhất (ở giữa dây). Nếu dây dao động với ba bụng thì bước sóng có giá trị là

Cho hệ bất phương trình \(\left\{ \begin{array}{l}x > 0\\2x - \frac{3}{2}y - 1 \ge 0\\4x - 3y - 2 \le 0\end{array} \right..\) Khẳng định nào sau đây là sai?