Một vật dao động cưỡng bức dưới tác dụng của một ngoại lực biến thiên điều hòa với tần số f. Chu kì dao động của vật là

Cho tứ diện \(ABCD\) có độ dài các cạnh bằng \(2a\). Gọi \(M,\,N\) lần lượt là trung điểm các cạnh \(AC\), \(BC\); \(P\) là trọng tâm tam giác \(BCD\). Mặt phẳng \(\left( MNP \right)\) cắt tứ diện theo một thiết diện có diện tích là \(\frac{{{a}^{2}}\sqrt{b}}{c}\). Khi đó hiệu \(b-c\) bằng bao nhiêu?

Cho hình hộp $ABCD.A^{\text{'}}{B}^{\text{'}}{C}^{\text{'}}{D}^{\text{'}}$ có thể tích bằng V. E, F lần lượt là trung điểm của $D{D}^{\text{'}}$ và $C{C}^{\text{'}}$ . Khi đó ta có tỉ số $\frac{V_{EABD}}{V_{BCDEF}}$ bằng?

Bảng tần số ghép nhóm cho ở bảng dưới:

Giá trị trung bình \(\overline x \) của nhóm mẫu số liệu là?

Trong trường hợp dưới đây, lượng cung bánh Trung thu cho thị trường nước ta năm 2022 không bị ảnh hưởng bởi các yếu tố nào sau đây?

"Vào thời điểm gần Tết Trung thu năm 2022, thị trường bánh trung thu trở nên sôi động. Nhu cầu đa dạng về chủng loại, mẫu mã bánh trung thu và xu thế tăng giá bán là những yếu tố thúc đẩy các nhà sản xuất tập trung nguồn lực cho sản phẩm này. Ngoài số doanh nghiệp sản xuất bánh kẹo với dây chuyền sản xuất hiện đại, công suất lớn chuyển sang làm bánh trung thu theo thời vụ, nhiều cơ sở sản xuất theo kiểu thủ công, qui mô nhỏ hơn, như các hộ cá thể trong các làng nghề truyền thống cũng gia nhập 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. 

Grand Opening of TIEU MINH Supermarket!

Welcome to the brand-new TIEU MINH Supermarket, where unbeatable offers await you! Join us as we celebrate our grand opening with special deals and discounts on a wide (7)_______of essentials, from groceries to household appliances and more!

Here’s what you can look forward to:

• Amazing discounts on a vast amount of products, including fresh foods, kitchenware, storage solutions, and (8)______ items.

• Exclusive “Buy One, Get the Other at 20% Off” deals on select items.

• A lucky draw with the chance to win (9)______for your home, perfect for upgrading your storage and kitchen spaces!

(10)______high prices, the items will be offered at a 30-50% discount without compromising quality. (11)______at our grand opening event to enjoy free samples, interactive games, and live demos from top brands. Our rewards program also lets you earn points and receive exclusive member(12)_______.

Phát triển bền vững thể hiện ở chỗ:

Dòng nào nêu đúng khái niệm về luận cứ trong văn nghị luận?

Đoạn trích mang đến cho người đọc nhận thức gì về Tổ quốc xưa và nay?

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.

MAKE A DIFFERENCE – VOLUNTEER TODAY!

Let’s look at how volunteering can change lives and improve our community.

Facts and Figures:

Did you know that millions of people volunteer every year? Volunteers help in hospitals, schools, animal (7)________, and community centers. They bring people together, improve lives, and support those in need. Studies (8)________ that people who volunteer feel happier and more connected to their (9)________.

Positive Actions!

Find a cause you care about. (10)_________ it’s helping children, protecting the environment, or caring for animals, there are many ways to get involved.

Start small and be consistent. Even a few hours a month can make a big (11)________. Volunteering regularly helps build trust and strong connections with those you help.

 Learn new skills and meet (12)________ people. Volunteering is a great way to gain experience and make friends, all while helping others.

Đảo nào dưới đây nằm ở phía Bắc của Nhật Bản?

Read the following advertisement 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 1 to 6.

During the 1960s and '70s, industrialised countries suffered a(n) ______(1), and violent crimes such as muggings increased at an alarming rate. What is more, it was expected to ______(2) worse. Only it didn't. Instead, it got much, much better. In the 1990s, crime started to fall dramatically, and today it is down by almost 50% across the industrialised world and continues to fall. Triumphant politicians will assert that their policies have cut crime. Actually______(3) of the country's policies, the trend does coincide ______(4) the use and subsequent prohibition of tetraethyl lead in petrol, ______(5) for years as a cause of aggressive behaviour. Therefore, countries that still use leaded petrol are being urged to stop ______(6) it to help improve health and crime prevention.

Chủ thể tiêu dùng có vai trò gì sau đây?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks.

I was an MBA student in the USA and I lived in the university’s coed dormitory. In my culture, usually, if a woman talks to a man, it is a sign of romantic interest. (34)_____, in the first few days of school, I found it strange that so many women were talking to me and I was under the impression that some women on my dormitory floor were interested in me. To (35)__________ their politeness, I would buy   them flowers or offer small gifts, as is done in my country. However, I was quite surprised to see that these same women now  seemed (36)______around me. One was even quite offended and told me to leave her alone. Eventually I talked to the residence adviser on my floor to see what I was doing wrong, and he explained to me the way men and women usually interact in the USA. I was quite relieved to hear that (37)____ was wrong with me, but rather with the way I was interpreting my conversations with    women. Even though I did not find the love of my life while I was in the USA, I still made many good female friends afterwards (38)______I still maintain contact.

Read the following advertisement/announcement and mark the letter A, B, C, or D on your answer sheet to indicate the correct option that best fits each of the numbered blanks from 1 to 6.

DISCOVER THE IPHONE 16

Looking for a smartphone that redefines innovation? The iPhone 16 is the perfect blend (1) ______
cutting-edge technology and sleek design. With its stunning Super Retina XDR display, you’ll experience vibrant colors and incredible detail. Whether you’re capturing photos or streaming videos, this device offers unparalleled performance. Want to enhance your (2) ______? The iPhone 16 features the powerful A16 Bionic chip, (3) ______ lightning-fast speeds for all your tasks. Plus, with its (4) ______, you can stay connected longer without worrying about (5) ______. With the introduction of Apple Intelligence and new AI-driven audio and visual features, Apple has once again pushed the boundaries of what a smartphone can do. Many of the predictions about the iPhone 16 were right on target, and the launch has received an enthusiastic response from the public. Apple has certainly raised the bar and has (6) ______ a new standard for the future of smartphones.

Read the passage carefully

1. Millions of people are using cellphones today. In many places, it is actually considered unusual not to use one. In many countries, cellphones are very popular with young people. They find that the phones are more than a means of communication - having a mobile phone shows that they are cool and connected.

2. The explosion in mobile phone use around the world has made some health professionals worried. Some doctors are concerned that in the future many people may suffer health problems from the use of mobile phones. In England, there has been a serious debate about this issue. Mobile phone companies are worried about the negative publicity of such ideas. They say that there is no proof that mobile phones are bad for your health.

3. On the other hand, medical studies have shown changes in the brain cells of some people who use mobile phones. Signs of change in the tissues of the brain and head can be detected with modern scanning equipment. In one case, a traveling salesman had to retire at young age because of serious memory loss. He couldn't remember even simple tasks. He would often forget the name of his own son. This man used to talk on his mobile phone for about six hours a day, every day of his working week, for a couple of years. His family doctor blamed his mobile phone use, but his employer's doctor didn't  agree.

4. What is it that makes mobile phones potentially harmful? The answer is radiation. High-tech machines can detect very small amounts of radiation from mobile phones. Mobile phone companies agree that there is some radiation, but they say the amount is too small to worry about.

5. As the discussion about their safety continues, it appears that it's best to use mobile phones less often. Use your regular phone if you want to talk for a long time. Use your mobile phone only when you really need it. Mobile phones can be very useful and convenient, especially in emergencies. In the future, mobile phones may have a warning label that says they are bad for your health. So for now, it's wise not to use your mobile phone too often.

Choose an option (A, B, C, or D) that best answers each question:

According to the passage, what can be inferred about cellphones?

Ở một loài cá, người ta phát hiện ra rằng con cái có khả năng chuyển giới thành con đực khi môi trường sống thiếu vắng con đực. Điều này có thể là một lợi thế tiến hóa của loài cá này. Dựa trên kiến thức về sinh sản ở động vật, cơ chế nào sau đây có thể giải thích cho hiện tượng này và lợi ích tiến hóa của nó?

Cho hình chóp S.ABC. Gọi M, N lần lượt là trung điểm của SA và SB. Khẳng định nào sau đây đúng? 

Trong một khu rừng, người ta ước tính đang có 800 con hà mã, 1500 con cá sấu và 2100 con ngựa vằn. Tốc độ tăng trưởng của hà mã là \(4 \%\) mỗi năm, trong khi đó số ngựa vằn lại giảm \(3 \%\) mỗi năm. Số lượng cá sấu tăng \(2 \%\) mỗi năm.

Sau 10 năm, số lượng ngựa vằn còn lại trong rừng gần nhất với giá trị nào sau đây?

Giá trị nào dưới đây có 2 chữ số có nghĩa (CSCN)?