Trong không gian Oxyz, cho vectơ a=(2;−1;5). Tọa độ vectơ −5a là
Câu hỏi liên quan
Đọc đoạn thông tin và chọn đúng hoặc sai ở mỗi ý a, b, c, d sau đây:
“Thiên nhiên nhiệt đới ẩm gió mùa làm cho quá trình phong hóa diễn ra mạnh mẽ và xâm thực phổ biến ở đồi núi.”
a) Phong hóa lý học là quá trình chủ yếu trong điều kiện khí hậu lạnh.
b) Xói mòn và rửa trôi đất là hiện tượng phổ biến ở vùng đồi núi.
c) Phong hóa hóa học mạnh làm biến đổi nhanh lớp vỏ phong hóa.
d) Tác động xâm thực, rửa trôi là hệ quả tích cực trong quá trình phong hóa.
Một vật được ném từ độ cao H với vận tốc ban đầu v0 theo phương nằm ngang. Bỏ qua sức cản của không khí, tầm xa L tăng 2 lần khi
- NaHCO3 được sử dụng là phụ gia thực phẩm với tên gọi baking soda, có kí hiệu là E500 dùng làm chất điều chỉnh độ chua trong sốt cà chua, nước ép hoa quả,… Khi đó, NaHCO3 sẽ tác dụng với H+ để làm giảm nồng độ H⁺. Vai trò của NaHCO3 trong phản ứng là
CHỦ ĐỀ: THẾ GIỚI TUYỆT ĐẸP…
(Tham khảo bài văn của chủ đề trong đường link dưới đây ở trang 21)
https://tvsthpt.dlib.vn/app/doc-sach-ebook/d02db18272fe
Và trả lời câu hỏi sau:
Từ thông tin của bài đọc, hãy hoàn thành nhận xét sau bằng cách kéo thả các từ vào đúng vị trí.
Bằng thao tác lập luận (...a...), tác giả đã phủ định ý kiến cho rằng khoa học là khô khan, lạnh lùng và đưa ra những lập luận thuyết phục để chứng minh khoa học có sự giao thoa với (...b...). Khoa học đẹp bởi vì thế giới thực sự đẹp từ trong bản chất của nó. Và khoa học đã phát hiện ra những vẻ đẹp của (...c...) thế giới qua sự khám phá, nghiên cứu, tìm tòi.
Ý tưởng kinh doanh là những suy nghĩ, hành động
Vì sao chúng ta cần ăn prôtêin từ các nguồn thực phẩm khác nhau?
chọn đúng hoặc sai với mỗi ý a), b), c), d)
Một khối khí đựng trong xilanh có pít-tông. Đốt nóng xilanh trong thời gian đủ dài (trong quá trình đốt pít-tông không dịch chuyển).
Lưu trữ trực tuyến ra đời giúp khắc phục điều gì sau đây?
Read the following passage about urban shift and mark the letter A, B, C, D on your answer sheet to indicate the best answer to each of the following questions from 31 to 40.
[I] Sperm whales are fascinating creatures. [II] They possess the biggest brain of any species, six times larger than a human’s, which scientists believe may have evolved to support intelligent, rational behavior. [III] They’re also highly social and capable of making decisions as a group. [IV] But there’s also a lot we don’t know about them, including what they may be saying to one another when communicating with a system of short clicks, known as codas.
Now, new research published in Nature Communications today suggests that sperm whales’ communication is actually much more expressive and complicated than was previously thought. A team of researchers led by Pratyusha Sharma at MIT’s Computer Science and Artificial Intelligence Lab (CSAIL) working with Project CETI, a nonprofit focused on using AI to understand whales, used statistical models to analyze whale codas and managed to identify a structure to their language that’s similar to features of human language. Their findings represent a tool future researchers could use to decipher not just the structure but the actual meaning of whale sounds.
For the study, the researchers examined recordings of 8,719 codas from around 60 whales collected by the Dominica Sperm Whale Project between 2005 and 2018, using a mix of AI algorithms for pattern recognition and classification. The AI then turned the clicks within the coda data into a new kind of data visualization called an exchange plot, revealing that some codas featured extra clicks. These extra clicks, combined with variations in the duration of their calls, appeared in interactions between multiple whales, which they say suggests that codas can carry more information and possess a more complicated internal structure than we had previously believed.
The team’s next step is to build language models of whale calls and to examine how those calls relate to different behaviors. They also plan to work on a more universal system that could be used across species, says Sharma. Taking a communication system we know nothing about, working out how it encodes and transmits information, and slowly beginning to understand what’s being communicated could have many purposes beyond whales. “I think we’re just starting to understand some of these things,” she says. “We’re very much at the beginning, but we are slowly making our way through.”
Which of the following best summarises paragraph 2?
Phong trào Tây Sơn mang tính chất:
Read the following passage about food addiction 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.
Few people would disagree that one of the world's most popular dishes is pizza. Twenty-two-year-old Zack certainly wouldn't. He would eat a variety of pizza-based items, including homemade pizza, precooked microwave pizza, and even pizza leftovers from the night before. He was consuming 800kg of pizza a year. As a child, Zack had eaten a wide variety of food. But he became addicted to pizza when he started secondary school. American school meals have often been criticised for the large amount of fast food present on the menu, and pizza is the star dish. Zack even spent all his pocket money on slices of pizza.
Naturally, Zack's family worried about his high-calorie, low-vitamin diet. So did Zack. In an attempt to break his addiction, Zack agreed to appear on a TV programme called Freaky Eaters. Its aim was to encourage food addicts to beat their addictions with the help of a psychologist and nutritionist. It wasn't easy. He had to eat a fish dish, while his brother sat in front of him enjoying... a pizza! However, Zack met the challenge and has never eaten pizza again.
Seventeen-year-old Stacy Irvine's friends visit her and discover that she has been rewarded thousands of free toys from fast food restaurants as a regular customer. Stacy's mother often gave her two-year-old girl a portion of fried chicken in a McDonald's restaurant. [I] Since then, Stacy has refused to eat anything else except for pieces of fried chicken, and as a result, her diet has created serious health. She has been warned that if she doesn't change her diet, she will die. [II] Stacy once collapsed due to lack of vitamins and nutrients and needed to be hospitalised. [III] She insisted that Stacy adopt a healthier lifestyle. However, worryingly, Stacy's mother said that while Stacy was beginning to understand the seriousness of her situation, she couldn't eat anything else but chicken nuggets. [IV]
Twenty-year-old Hanna Little was keen on chips. The only thing that Hanna consumed for fifteen years was one plate of chips after another. Not surprisingly, a diet that contained few nutrients and an excess of fat and carbohydrates could only have negative consequences. And it did because not only did Hanna develop health problems, but she also had to leave her job after collapsing at work. At five, Hanna became addicted to chips and refused to eat fruits and vegetables despite her mother's efforts. Hanna says that she was terrified of tasting the flavour of different types of food and she would feel anxious just at the idea of doing it. Parties, picnics and barbecues with friends and family used to be a nightmare. Furthermore, Hanna was soon seen as 'odd' by her friends' parents.
It wasn't until the age of sixteen that Hanna realised she had Selective Eating Disorder (SED). Despite this new knowledge, no solution was found. It wasn't until she lost her job before she started eating normally. Hanna sought therapy from psychologist Felix Economakis, who used hypnosis, a treatment that none of the doctors that she had seen before had mentioned, to get her to eat fruit after one one-hour session, and since then she has been willing to eat anything.... including chips!
(Adapted from Friends Global)
According to paragraph 1, which one is NOT MENTIONED as pizza-based items?
Đặc điểm kinh tế của các quốc gia cổ đại phương Đông là gì?
Chủ thể nào trong tình huống dưới đây đã thực hiện đúng quyền tiếp cận thông tin của công dân?
"Chị V và anh K muốn tìm hiểu thông tin về bồi thường, hỗ trợ tái định cư đối với hộ gia đình khi Nhà nước thu hồi đất trên địa bàn huyện mình để xây dựng các công trình công cộng. Hai người đến Uỷ ban nhân dân huyện đề nghị được cung cấp thông tin về những nội dung này. Sau khi nghe chị V và anh K trình bày về mong muốn của mình, ông T (cán bộ lãnh đạo huyện X) đã từ chối cung cấp thông tin với lý do: đây là những tài liệu mật, không được phép công khai".
Mark the letter A, B, C or D on your answer sheet to indicate the best arrangement of utterances or sentences to make a meaningful exchange or text in each of the following questions from 13 to 17.
a. Anna: I’m planning to visit Spain next year.
b. Tom: Why are you learning Spanish?
c. Tom: Oh, that’s exciting! How are your lessons going so far?
d. Anna: They’re going well. I’m learning a lot about Spanish culture too.
e. Tom: That sounds fascinating!
Một vật được làm lạnh từ xuống Nhiệt độ của vật theo thang Kelvin giảm đi bao nhiêu độ?
Quá trình khử nitrate là gì?
Cường độ ánh sáng tăng trong ngưỡng sinh lí có tác động
Khi mức độ lạm phát vừa phải sẽ có tác dụng như thế nào?
Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that best combines each pair of sentences in the following questions.
Sunbathing is still a popular activity. People do it even though they know it can cause cancer.
Đồ thị độ dịch chuyển – thời gian của một người đang bơi trong một bể bơi dài 50 m. Trong 20 giây cuối cùng, vận tốc của người đó là bao nhiêu?