Hai bạn Việt và Nam mỗi người thực hiện một thí nghiệm một cách độc lập với nhau. Xác suất thực hiện thành công thí nghiệm của Việt và Nam lẩn lượt là 0,6 và 0,7. Xác suất có đúng một trong hai người thực hiện thành công thí nghiệm biết rằng có ít nhất một người thực hiện thành công thí nghiệm là \(\frac{{\rm{a}}}{{\rm{b}}}\) với \({\rm{a}},{\rm{b}} \in \mathbb{N},{\rm{b}} < 50.\) Giá trị của \({\rm{a}} + {\rm{b}}\) là bao nhiêu?

Read the following passage about the e-waste crisis and mark the letters A, B, C, or D on your answer sheet to indicate the best answer to each of the following questions from 31 to 40.

     [I] Electronic waste, commonly known as e-waste, refers to discarded electronic devices like smartphones, computers, and household appliances. [II] As technology rapidly advances, many of these devices become outdated quickly, leading to an increase in e-waste globally. [III] Experts estimate that millions of tons of e-waste are generated annually, and the numbers continue to rise as people upgrade their gadgets more frequently. [IV]

     The improper disposal of e-waste presents significant environmental and health risks. When e-waste is dumped in landfills, it often releases harmful chemicals, such as lead and mercury into the soil and water, which can wreak havoc on ecosystems and pose serious health risks to nearby communities. Moreover, a large portion of e-waste is transported to developing countries, where regulations on electronic disposal may be less strict. Here, workers, often without adequate protection, dismantle electronic devices by hand to retrieve valuable metals like gold and copper, exposing themselves to toxic substances.

     To address this growing problem, many countries and organizations are promoting e-waste recycling programs. These initiatives encourage consumers to recycle old electronics responsibly, rather than discarding them. By doing so, valuable materials can be reused, reducing the demand for mining new resources and helping to minimize environmental damage. Additionally, some companies are adopting sustainable design strategies, producing products that are easier to repair or upgrade, thereby extending their lifespan.

     Public awareness about the impacts of e-waste is gradually increasing, and more people are becoming motivated to make eco-friendly choices. However, achieving global cooperation remains challenging, as effective solutions require collaboration across borders.

 (Adapted from The Guardian)

Read the following passage about green living habits 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.

     In an era marked by climate change and environmental degradation, adopting green living habits has become increasingly vital. Green living refers to a lifestyle that seeks to minimize one’s ecological footprint through conscious choices in daily activities. This can include everything from reducing waste to conserving energy and using sustainable products. As more individuals recognize the importance of preserving our planet, the movement toward greener practices continues to gain momentum. 

     One of the most significant aspects of green living is its focus on sustainability. By choosing products that are eco-friendly, consumers can support businesses that prioritize environmental responsibility. For instance, using reusable bags, bottles, and containers reduces plastic waste and promotes a circular economy. Furthermore, opting for locally sourced foods not only supports local farmers but also decreases the carbon emissions associated with transportation.

     When green living habits are adopted, they can lead to profound changes in our environment. By reducing their energy consumption through the use of energy-efficient appliances, individuals help lower greenhouse gas emissions. Consequently, this contributes to cleaner air and mitigates the effects of climate change. Moreover, by practicing water conservation methods, such as fixing leaks and using low-flow fixtures, households can significantly decrease water waste, promoting the sustainable use of this precious resource.

     In conclusion, educating individuals about green living habits is crucial for promoting a more sustainable future. Schools and community organizations can offer workshops and resources that highlight the benefits of eco-friendly practices. Additionally, social media campaigns can raise awareness and encourage people to share their experiences with sustainable living. By empowering individuals to make informed choices, we can collectively work toward a healthier planet for generations to come.

Taking selfies, a cultural phenomenon, (18) ______. A selfie is a self-portrait taken with a smartphone or camera. This trend has gained immense popularity, especially among younger generations, (19) ______. The ease of taking and sharing selfies has made them a staple in modern communication.

     Selfies serve various purposes beyond just capturing images. (20) ______. Additionally, selfies can be a form of self-expression, as individuals often choose specific angles, filters, and settings to convey their mood or personality. This ability to curate one’s image has led to the rise of social media influencers who rely on selfies to connect with their audiences and promote brands.

     However, the selfie trend is not without its criticisms. Constantly judged by others on social media, (21) ______. Some argue that the obsession with selfies can lead to unrealistic

beauty standards and a distorted self-image. (22) ______.