Một lượng lớn soda được điều chế bằng phương pháp Solvay bằng cách cho khí CO₂ vào dung dịch NaCl bão hoà và NH₃ bão hoà. Đặc điểm của phương pháp này là

Cơ chế của thị trường tồn tại các nhược điểm gì?

Read the following passage 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.

Mountain Lions Amid Wildfires: A Struggle for Survival

Beth Pratt, the California director for the National Wildlife Federation, has spent her career protecting Los Angeles’ mountain lions. These top predators live in a rocky area surrounded by fancy houses and many roads. When wildfires destroy vast stretches of open land, the survival options for these animals become critically limited. “This is the LA area—these mountain lions can’t just move into the Kardashians’ backyard,” Pratt says, her voice filled with concern for the animals in such a difficult situation.

(I) The chaparral vegetation, covering about 10% of California, is one of the world’s most flammable ecosystems. (II) In Los Angeles, suburban sprawl intrudes on these areas, blocking wildlife escape routes. (III)Fires strip the land of food and shelter, transforming vibrant ecosystems into barren landscapes. (IV) Pratt highlights the urgency of the situation, explaining how areas that once supported life are now “taken out of commission,” leaving many species to starve or struggle for survival.

The consequences extend beyond wildlife. Wildfires have caused devastating human losses, with 88,000 people evacuated and a rising death toll of 25. Meanwhile, the non-human world suffers equally, particularly endangered species with limited ranges. Red-legged frogs, reintroduced into Santa Monica streams in 2014, are among the most affected, with their habitats repeatedly destroyed. The Woolsey Fire of 2018 was followed by mudslides that wiped out much of the region's delicate ecosystem, and scientists fear similar outcomes this time. California newts, reptiles, and snakes are also at high risk, while mammals and birds, although more likely to escape, face challenges in finding food and shelter as the ecosystem bounces back.

Despite the devastation, hope remains. The chaparral is a fire-adapted ecosystem, and life often endures beneath the soil. Seeds can survive and germinate quickly, with grasses sprouting weeks after the first rain. Shrubs may take up to a decade to recover, depending on rainfall. Prof. Stefan Doerr, an expert on wildfires, emphasizes the resilience of this landscape, noting its evolutionary adaptation to high-intensity fires occurring every 30 to 100 years. While the aftermath looks bleak, these fires play a role in maintaining biodiversity, offering a glimmer of hope for recovery.

Which of the following best summarizes the main point of the passage?

Cho các mệnh đề:

$A$: "Tổng hai cạnh của một tam giác lớn hơn cạnh còn lại".

$B$: "$\exists x \in \mathbb{R}: \, x^2+5x-6=0$".

$C$: "$\sqrt{125}$ là số nguyên".

$D$: "Phương trình: $x^4+2x^2+3=0$ có nghiệm".

Trong các mệnh đề phủ định của các mệnh đề trên có bao nhiêu mệnh đề đúng?

Cho tứ diện \(A B C D\) có \(A C=A D=B C=B D=a\) và hai mặt phẳng \((A C D),(B C D)\) vuông góc với nhau. Tính độ dài cạnh \(C D\) sao cho hai mặt phẳng \((A B C),(A B D)\) vuông góc với nhau.

Ở Trung Quốc, vương triều nào được thành lập đầu tiên trong thời cổ đại?

Khi nói về ảnh hưởng của các nhân tố môi trường đến quá trình hô hấp ở thực vật, phát biểu nào sau đây sai?

Chủ thể nào sau đây đang tiến hành hoạt động sản xuất?

Nguyên tố X có Z = 12. Khi nguyên tử nguyên tố X nhường đi 2 electron thì tạo thành ion X²⁺ có cấu hình electron là

Read the following passage about fitness trends 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.

FITNESS TRENDS

[I] Reformer Pilates is an advanced and more intense variation of traditional Pilates. [II] Since this type of equipment isn’t something you would typically have at home, you’ll need to visit a specialized Pilates center to try it. [III] While it might look easy at first, don’t be fooled - by the end of the session, your thighs will be burning, and you might struggle to walk up or down stairs for a few days afterward. [IV] This workout pushes your body to its limits, providing a more challenging experience than standard Pilates, and many find it an effective way to build both strength and flexibility.

Trampolining is another popular fitness trend, and although it may seem like child's play, it’s actually a highly effective workout. Jumping up and down on a trampoline can leave you feeling exhausted after just a few minutes. Surprisingly, it’s even better for heart health than running, while also improving coordination and helping to reduce stress levels. Trampolining is gaining widespread popularity, with new centers popping up that feature as many as 150 trampolines. These facilities offer options for everyone: you can enjoy 'freejumping,   where you bounce without an instructor, or pay for professional lessons to learn the best techniques and get the most out of your workout. Many people are discovering that trampolining combines fun and fitness in a way that makes staying active much more enjoyable.

If you're someone who is typically active but feeling down or emotionally drained, Dynamic Running Therapy might be just what the doctor ordered. This trend involves running with a therapist, combining the benefits of physical exercise with talk therapy. Though these sessions are often more expensive than typical therapy sessions because of the professional fees, they offer significant advantages. Running while talking helps distract you from any discomfort, allowing you to cover longer distances, and creates a relaxed, open environment that can make it easier to talk compared to the usual therapist’s office setting.

Which of the following best summarizes paragraph 3? 

Choose the correct answer.

My parents _____ buy me a new MP3 player if I pass the exam.

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. 

HASTAG ACTIVISM - WORTH CLICKING ON?

Platforms like Facebook and Twitter are being used more and more to ___(1)___ awareness of social issues and ___(2)___ for good causes. There have been several examples of ___(3)___ campaigns in recent years. For instance, the #IceBucketChallenge proved a viral success in raising awareness and funds ___(4)___ ALS, a disease that ___(5)___. Not only did people all over the world post videos of themselves tipping a bucket of iced water over their heads, ___(6)___ they also nominated other people to do the challenge, as well as donating to the Association.

(Adapted from Friends Global)

Khi nghi ngờ vật nuôi bị mắc cúm gia cầm cần thực hiện mấy công việc cần thiết?

Để xóa 2 phần tử ở vị trí 1 và 2 trong danh sách a hiện tại ta dùng lệnh nào?

Cho biết ý nào đúng nhất: Thành phần các loài sinh vật được thể hiện qua chỉ số?

Trang web của một công ty kinh doanh trò chơi trực tuyến có đăng bản giới thiệu về trò chơi. Nội dung bài giới thiệu và các video minh họa được dịch và lầy từ trang web của nhà sản xuất game nước ngoài. Công ty chưa liên hệ đề xin phép nhà sản xuất đó. Vậy công ty đã vi phạm Luật Sở hữu trí tuệ tại các khoản nào của Điều 28 Luật Sở hữu trí tuệ số 50/2005/QH11 (sửa đôi bỗ sung năm 2019)?