Nước cứng ảnh hưởng nhiều đến các hoạt động trong sản xuất và đời sống, vì vậy trong sinh hoạt và sản xuất cần làm mềm nước, tức là điều chỉnh lượng ion Ca²⁺ và Mg²⁺ trong nước xuống ngưỡng mà tại đó nước được coi là nước mềm. Cho các phát biểu:

(a) Đun sôi có thể làm mất tính cứng tạm thời của nước.

(b) Dùng Na₂CO₃ để làm mất tính cứng tạm thời và tính cứng vĩnh cửu của nước.

(c) Dùng HCl để làm mất tính cứng tạm thời của nước.

(d) Dùng Ca(OH)₂ với lượng vừa đủ để làm mất tính cứng vĩnh cửu của nước.

Trong các phát biểu trên, số phát biểu đúng là

Lông hút ở rễ do tế bào nào sau đây phát triển thành?

Nhận xét nào sau đây đúng về tư tưởng Hồ Chí Minh?

Nhằm khắc phục tình trạng khủng hoảng trong những năm 1850 – 1870, chính phủ đế chế II do Na-pô-lê-ông III đứng đầu đã có quyết định gì?

Hãy lựa chọn đúng hoặc sai đối với các nhận định sau về môn Địa lí.

Phát biểu nào sau đây sai?

Năm 1912, Phan Bội Châu thành lập Việt Nam Quang phục hội ở Quảng Châu (Trung Quốc) với tôn chỉ duy nhất là

Hãy cho biết: Tính lãnh thổ tạo ra mô hình phân phối nào?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 28 to 34. Foot-racing is a popular activity in the United States. It is seen not only as a competitive sport but also as a way to exercise, to enjoy the camaraderie of like-minded people, and to donate money to a good cause. Though serious runners may spend months training to compete, other runners and walkers might not train at all. Those not competing to win might run in an effort to beat their own time or simply to enjoy the fun and exercise. People of all ages, from those of less than one year (who may be pushed in strollers) to those in their eighties, enter into this sport. The races are held on city streets, on college campuses, through parks, and in suburban areas, and they are commonly 5 to 10 kilometers in length. The largest footrace in the world is the 12-kilometer Bay to Breakers race that is held in San Francisco every spring. This race begins on the east side of the city near San Francisco Bay and ends on the west side at the Pacific Ocean. There may be 80,000 or more people running in this race through the streets and hills of San Francisco. In the front are the serious runners who compete to win and who might finish in as little as 34 minutes. Behind them are the thousands who take several hours to finish. In the back of the race are those who dress in costumes and come just for fun. One year there was a group of men who dressed like Elvis Presley, and another group consisted of firefighters who were tied together in a long line and who were carrying a fire-hose. There was even a bridal party, in which the bride was dressed in a long white gown and the groom wore a tuxedo. The bride and groom threw flowers to bystanders, and they were actually married at some point along the route.

Which of the following is NOT implied by the author?

Những cơ chế nào dưới đây giúp tăng bài tiết nước tiểu?

1. Lượng nước trong cơ thể tăng.

2. Áp suất thẩm thấu giảm.

3. Huyết áp tăng.

4. Cơ thể dư thừa nước.

Một lợi ích của việc lưu trữ dữ liệu trên đám mây là gì?

Hai xe xuất phát cùng lúc từ hai vị trí A và B cách nhau 75 km. Xe 1 xuất phát từ A đến B với tốc độ 40 km/h và xe 2 xuất phát từ B đến A với tốc độ 35 km/h. Giả sử hai xe chuyển động thẳng đều. Hỏi sau khi rời bến bao lâu thì hai xe gặp nhau và vị trí gặp nhau cách A là bao nhiêu?

Thủ pháp nghệ thuật nổi bật nhất trong đoạn trích trên là

Read the following passage about green living 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 23 to 30

          Green living refers to a lifestyle that promotes sustainability and environmental consciousness. This way of life encourages individuals to make choices that reduce their carbon footprint and conserve natural resources. Practices such as recycling, using renewable energy sources, and reducing waste are fundamental aspects of green living. By adopting these practices, individuals can contribute to the preservation of the environment and promote a healthier planet for future generations.

          One significant component of green living is the use of renewable energy sources. Solar, wind, and hydroelectric power are examples of renewable energy that can replace fossil fuels. Using renewable energy reduces greenhouse gas emissions and dependence on non-renewable resources. Additionally, renewable energy sources are often more sustainable and have less impact on the environment.

          Another important aspect of green living is sustainable consumption. This involves choosing products that are environmentally friendly and responsibly sourced. For example, buying locally produced food reduces the carbon footprint associated with transportation. Moreover, opting for products made from recycled materials helps conserve resources and reduce waste.

          Green living also emphasizes the importance of conserving water and energy. Simple actions such as turning off lights when not in use, fixing leaks, and using energy-efficient appliances can significantly reduce energy and water consumption. These practices not only benefit the environment but also save money on utility bills.

          Education and awareness play a crucial role in promoting green living. By educating individuals about the benefits of sustainable practices and how to implement them, communities can foster a culture of environmental responsibility. Awareness campaigns, workshops, and educational programs are effective ways to encourage people to adopt green living practices.

In which paragraph does the writer explore the role of education in green living? 

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.

STAY SAFE ON FACEBOOK

Let’s protect your privacy & security

1.    Privacy risks: Facebook collects a large (7) ______ of personal information. This information is often used for targeted advertising but could also be accessed by unauthorized third parties. Always be (8) ______ of what you share like your phone number, address, or financial information.

What you can do:

●        Adjust your privacy (9) ______ to limit who can see your posts and personal details.

●        Think twice before sharing information that could be misused.

2.    Security tips: Your Facebook account can be a target for hackers. Cybercriminals may attempt to steal your login information or infect your device with malware.

What you can do:

●        Enable two-factor authentication (2FA): This adds an extra layer of security, making it harder for (10) ______ to access your account.

●        Use strong, unique passwords: (11) ______ using the same password across multiple sites, make your Facebook password complex.

●        Beware of scams: Don’t click on suspicious links or download files from unknown sources. Always (12) ______ the sender’s identity before responding to messages.

Tập nghiệm của bất phương trình ${{\log }_{2}}\left(x-1 \right)\lt 3$ là