Trong không gian với hệ tọa độ Oxyz, cho ba vectơ \(\vec{a}=\left( 5;7;2 \right),\vec{b}=\left( 3;0;1 \right),\vec{c}=\left( -6;1;-1 \right)\). Tọa độ của vectơ \(\vec{m}=3\vec{a}-2\vec{b}+\vec{c}\) là

Cơ chế thị trường tự điều chỉnh tuân theo yêu cầu của các quy luật kinh tế nào?

Read the passage carefully

1. 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.

2. 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.

3. 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.

4. 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.

5. 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.

Choose an option (A, B, C, or D) that best answers each question:

According to the passage, what can be inferred about cellphones?

Đâu là nhận xét đúng về yếu tố lịch sử trong văn bản Truyện An Dương Vương và Mỵ Châu - Trọng Thủy?

Con hãy lựa chọn đáp án Đúng hoặc Sai

Văn bản Chiến thắng Mtao Mxây là đoạn giữa của sử thi Đăm Săn, đúng hay sai?

Vai trò của ngân sách nhà nước thể hiện như thế nào trong những trường hợp sau: Ngân hàng Nhà nước quyết định giảm lãi suất điều hành để hỗ trợ doanh nghiệp và người dân bị thiệt hại do ảnh hưởng của thiên tai, dịch bệnh.

Vào những năm 1670, Antonie van Leewenhoek đã phát hiện ra nguyên sinh động vật nhờ quan sát mẫu vật nào?

Xét khối khí trong một xilanh đặt nằm ngang. Khi truyền nhiệt lượng X joule (J) cho khối khí, khối khí nở ra đẩy pit-tông dịch chuyển đều, làm thể tích khối khí tăng thêm 9 cm³ và nội năng của khối khí tăng thêm 0,4 J. Biết trong quá trình đó áp suất khối khí không đổi và bằng \(10^5\) Pa. Xác định giá trị X.

Phát biểu nào là hợp lí nhất về cơ cấu hàng xuất khẩu?

Mark the letter A, B, C or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions:

Most of the classmates couldn't come. He invited them to the birthday party.

Trong quang hợp, pha sáng cung cấp cho pha tối chất gì?

Read the following passage about the impact of tweeting on everybody 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

EVERYBODY’S TWEETING

Twitter (18) ________________ for a podcasting website, but then people realized that it offered them the power to connect with millions of people instantly. Suddenly, everyone had a voice, as long as it wasn’t longer than 140 characters. But what are we using it for, and just how is Twitter changing the way we do things?

Perhaps the greatest impact Twitter has had is on breaking news. Before Twitter, (19) _____________ before finally broadcasting it on the radio or TV. These days, anyone who happens to be in the right place at the right time with a Twitter account can post news the second it happens. For example, Janis Krums posted a photo and a tweet when he witnessed a US flight making an emergency landing in the Hudson River. He must never have imagined that he would break the story to the world.

Following Pop Idols

Young people have always loved to follow their pop idols, and Twitter has made it a whole lot easier. Before the Internet, teenagers used to join the fan clubs of their favorite bands and write letters to their heroes,

(20) _________________ to get a reply written by the club secretary. Today’s teenagers don’t need to wait. By following their idols on Twitter, they get all the news the minute it happens: their meals, activities, or even thoughts. And all the news comes directly from the bands themselves.

Creating Movements

Twitter allows people who think the same way to get together and (21) ______________. These problems may be cyberbullying, sexism, or racism. They can share information, organize campaigns, and put pressure on related departments. Twitter has given the man and woman on the street the power to make a difference.

Identifying the source of a piece of news

It’s good to get an idea of the background of a person who says or writes something. Are they an impartial expert or someone who wants to change your opinion to suit their own agenda? For example, this statement about a flu epidemic, “Patients can already spread the virus a day before they’ve even fallen sick themselves”, is more likely to come from a doctor than a politician. On the other hand, “We have to stop people who are carrying the virus from getting into the country” is more likely to come from a politician. (22) _____________, you’re better able to decide how much importance to give it and whether you can really trust what they say.

Phát biểu nào không đúng với công nghiệp điện?

Biểu thức nào sau đây là tam thức bậc hai

Ở ngô có bộ NST 2n = 20. Thể một nhiễm của ngô có bao nhiêu NST trong mỗi tế bào sinh dưỡng?

CHỦ ĐỀ: HÀNH VI TÌM KIẾM SỰ HỖ TRỢ CỦA PHỤ NỮ KHI MẮC TRẦM CẢM SAU SINH

(Tham khảo bài văn của chủ đề trong đường link dưới đây ở trang 21)

https://tvsthpt.dlib.vn/app/doc-sach-ebook/d00b996754ec

Và trả lời câu hỏi sau:

Ý nào có thể suy luận từ đoạn [6]?

Một gàu nước nặng 2kg ở đáy giếng có độ sâu h so với mặt đất tại nơi có gia tốc trọng trường \(g = 9,8m/{s^2}\)có thế năng là -98J. Độ sâu của giếng là