Một bạn học sinh thực hiện thí nghiệm về tính chất của protein như sau:

     Chuẩn bị: lòng trắng trứng, dung dịch HCl 1M, 3 ống nghiệm, đèn cồn.

     Tiến hành thí nghiệm:

Bước 1: Lấy khoảng 2 mL lòng trắng trứng cho vào mỗi ống nghiệm.

Bước 2:

- Ống nghiệm (1): Thêm vài giọt HCl 1M.

- Ống nghiệm (2): Hơ nóng nhẹ ống nghiệm trên ngọn lửa đèn cồn trong khoảng 1 phút.

- Ống nghiệm (3): Đun nóng ống nghiệm (3) trên ngọn lửa đèn cồn cho đến khi thấy có mùi khét.

Bạn học sinh quan sát các hiện tượng ở các ống nghiệm và đưa ra nhận xét. Nhận xét nào dưới đây là sai về hiện tượng có thể có trong các ống nghiệm?

Bộ máy nhà nước Cộng hoà xã hội chủ nghĩa Việt Nam gồm có mấy đặc điểm cơ bản?

Cho khối lăng trụ đứng ABCD.A'B'C'D' có đáy là hình vuông, \(BD = 2\), góc giữa hai mặt phẳng \((A'BD)\) và \((ABCD)\) bằng \(60^\circ\). Thể tích của khối lăng trụ đứng đã cho bằng bao nhiêu?

Đạo hàm của hàm số \(f\left( x \right)=\sqrt{\text{ln}\left( \text{ln}x \right)}\) là:

Theo em, hạn chế lớn nhất của máy tính hiện nay là?

Một nhiệt kế có phạm vi đo từ 253 K đến 1273 K, dùng để đo nhiệt độ của các lò nung. Phạm vi đo của nhiệt kế này trong thang nhiệt độ Celsius là

Khối lượng của nguyên tử oxygen là 16 amu. Vậy khối lượng của nguyên tử oxygen tính theo đơn vị gram là

Đối với động cơ xăng 4 kì, ở kì nạp, xi lanh sẽ hút:

Loại thuế được điều tiết trực tiếp vào thu nhập hoặc tài sản của người nộp thuế được gọi là gì?

Read the passage below and choose A, B, C or D.

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.

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.

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.

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.

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.

What is mentioned about the man who used his cellphone too often in paragraph 3?

Read the following passage about Stewart the Career Advisor Robot 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 18 to 22.

          Stewart is a smart robot that helps students find the right career. It was created to give career advice to students who are about to graduate. Stewart (18) ______. This modern robot uses advanced technology and a large amount of job information to guide students toward careers that match their skills and interests.

Stewart was developed by engineers and career experts from America (19) ______. With a sleek design and friendly personality, Stewart can analyze students’ strengths, school records, and personal preferences to give advice that matches student’s dream and skills. (20) ______.

          One of Stewart’s special features is his ability to have flexible conversations and understand students’ concerns. With natural language processing, Stewart (21) ______. Also, Stewart gives updated information about job trends, salaries, and internship opportunities.

          Many schools and universities now use Stewart in their career counseling programs. (22) ______ , making Stewart a valuable tool for students planning their careers.

Phủ định của mệnh đề "$n > 9$" là

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.

     Autonomous vehicles, which were once the stuff of science fiction, are now becoming a reality. Tesla, for instance, (18) ______. A month later, the company showcased its fully self-driving car in California and has continued to expand its fleet ever since. At one of these events, Tesla’s vehicle received a safety award from the National Highway Traffic Safety Administration in 2020, further validating its technology. During a presentation at the Consumer Electronics Show in 2021, Tesla highlighted its commitment to safety and innovation.

  The Tesla Model S is one of the most advanced electric vehicles (19) ______. Clearly, Tesla and other manufacturers are at the forefront of transforming the automotive industry. (20) ______. The vehicles are equipped with various sensors, cameras, and AI algorithms.

  (21) ______. These technologies enable the cars to navigate complex environments, such as city streets and highways, with minimal human intervention. This is a significant leap toward a future where autonomous driving becomes the norm.

   Thanks to continuous advancements in technology, (22) ______. Consumers can look forward to safer and more efficient transportation solutions.

Chỉ ra câu đúng, sai trong các câu sau.

Trong các hoạt động kinh tế cơ bản không bao gồm hoạt động nào sau đây?

Đâu là phương án đúng: Theo phương pháp chiếu góc thứ nhất, vị trí hình chiếu bằng?

Biết rằng gia đình cô Xuân có hai người con. Xác suất hai người con đều là con gái biết rằng người con đầu là con gái là: