Trong các mệnh đề sau, mệnh đề nào có mệnh đề đảo đúng?
Trong các mệnh đề sau, mệnh đề nào có mệnh đề đảo đúng?
A. Nếu một tứ giác đó là hình vuông thì tứ giác đó có bốn cạnh bằng nhau;
B. Nếu một tứ giác là hình thoi thì tứ giác đó có bốn cạnh bằng nhau;
C. Nếu một tứ giác là hình chữ nhật thì tứ giác đó có hai cặp cạnh đối bằng nhau;
D. Nếu một tứ giác là hình thoi thì tứ giác đó có hai đường chéo vuông góc với nhau.
Hãy suy nghĩ và trả lời câu hỏi trước khi xem đáp án
- A: Mệnh đề: Nếu một tứ giác là hình vuông thì tứ giác đó có bốn cạnh bằng nhau. Đảo lại: Nếu một tứ giác có bốn cạnh bằng nhau thì tứ giác đó là hình vuông (sai, vì hình thoi có 4 cạnh bằng nhau).
- B: Mệnh đề: Nếu một tứ giác là hình thoi thì tứ giác đó có bốn cạnh bằng nhau. Đảo lại: Nếu một tứ giác có bốn cạnh bằng nhau thì tứ giác đó là hình thoi (sai, vì hình vuông có 4 cạnh bằng nhau).
- C: Mệnh đề: Nếu một tứ giác là hình chữ nhật thì tứ giác đó có hai cặp cạnh đối bằng nhau. Đảo lại: Nếu một tứ giác có hai cặp cạnh đối bằng nhau thì tứ giác đó là hình chữ nhật (sai, vì hình bình hành có 2 cặp cạnh đối bằng nhau).
- D: Mệnh đề: Nếu một tứ giác là hình thoi thì tứ giác đó có hai đường chéo vuông góc với nhau. Đảo lại: Nếu một tứ giác có hai đường chéo vuông góc với nhau thì tứ giác đó là hình thoi (đúng).
Câu hỏi liên quan
Cho phản ứng nhiệt hạch có phương trình: \(_1^2{\rm{D}} + _Z^4{\rm{X}} \to _2^4{\rm{He}} + _0^1{\rm{n}}.\) Hạt nhân \(_Z^1{\rm{X}}\) có điện tích là
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 36 to 40.
Parents of a Tokyo elementary school are up in arms at being asked to pay 730 dollars for their child's school uniform. A public elementary school in Tokyo's upmarket Ginza district has decided to adopt new school uniforms designed by the luxury Italian designer Armani. The bespoke uniforms, which include a hat and bag, are priced at over 80,000 (730 dollars) each. Parents are angry at the school's decision and are protesting at what they view as the exorbitant price for a uniform of an eight-year-old child. The school said it wanted a designer uniform that represented the rich area of Ginza. School officials visited top department stores and decided to ask the fashion brand Armani to design the uniform.
The expensive uniform has created such a fuss that it has been discussed in Japan's parliament. One lawmaker said that since the school is public and not private, "a certain price range needs to be considered". Finance Minister Taro Aso said. "Clearly it's expensive. It would be tough if a student could not afford to pay for it." Japan's education minister said steps would be taken to ensure the financial burden placed on parents for uniforms, "would not be excessive". Twitter users said young children are not interested in designer clothes. The school principal said. "With humility, I take the criticism that the explanation has been insufficient and not well-timed. I will go on explaining carefully to those concerned."
Why did the school want such an expensive uniform?
Đặc điểm nào đúng với phần phía Tây của Liên bang Nga?
Read the following passage about lifelong learning 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.
My father was an enthusiastic traveller, but as he got older, he increasingly suffered from what he called “travel fever,” a vivid term for the acute anxiety felt before a journey, essentially due to uncertainty about all the things that could go wrong. Sadly, this eventually stopped him from going on holiday. Then I, too, started to suffer similar apprehension, so I consulted a psychotherapist. She recommended a small piece of cognitive behavioural therapy, which involved acknowledging the mental and physical symptoms of anxiety, but telling myself that these were essentially indistinguishable from feelings of excitement about the prospect of a journey. This reframing of my feelings has been reasonably effective – it’s one way of dealing with uncertainty.
It’s not just the uncertainty of travel that we all have to face. None of us knows what is going to happen, or what is currently going on outside our immediate knowledge, or the vast majority of what has happened in the past. Uncertainty has been called the “conscious awareness of ignorance,” and there is a lot we are ignorant about. We must navigate through life without complete information, and this fundamental uncertainty is an inescapable aspect of human existence.
We all have to live with this uncertainty and, as a statistician, it’s been my job to try to analyse data and assess some of the risks we face. (I)But some deal with uncertainty with more equanimity than others. (II) Psychological studies, as well as our own experience, reveal a wide variation in people’s responses, including those that are cognitive (how we think), emotional (how we feel), and behavioural (what we do). (III)For example, when faced with uncertainty, do you deny it or acknowledge it, does it put the wind up you or make you courageous, do you try to avoid it or approach it?(IV)
Of course, your response may depend on the context, just as an individual’s appetite for risk-taking can vary across different areas of their lives. I have known people who seemed to take huge physical risks, yet were very cautious with money. Numerous scales have been developed to measure how well people can deal with uncertainty, based on responses to statements ranging from “Unforeseen events upset me greatly” to “When it’s time to act, uncertainty paralyses me.” Those who score highly, and find it difficult to tolerate uncertainty, may also be at increased risk of clinically significant anxiety and depression.
Which of the following best summarizes the main point of the passage?
Công nghệ phổ biến trong lĩnh vực luyện kim, cơ khí gồm mấy loại?
Trong dao động điều hòa x = Acos(ωt + φ), tốc độ nhỏ nhất bằng:
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 from 7 to 12.
STAY SAFE: UNDERSTANDING SCAMS AND HOW TO PREVENT THEM
What is a scam?
A scam is a deceptive scheme delivered through digital communications with the intent to steal money or personal information. These schemes take many forms, including online fraud, phishing emails, and fake lotteries. In (7) _____ words, scams are tricks that prey on your trust and can lead to significant financial loss.
Common types of scams
- Phishing: fraudulent emails or messages that appear to be from legitimate sources, tricking you into (8) _____ personal information.
- Lottery scams: notifications claiming you’ve won a (9) _____, requiring you to pay a fee to claim it.
- Other scams: these can include fake charities, advance-fee scams, and online auction fraud, each designed to exploit individuals in different ways.
Tips to prevent scams
- Verify sources: always check the (10) ____ of requestions for personal information.
- Root out suspicious communications: don’t engage with unknown contacts and report any suspicious emails or calls to the authorities (11) _____ potential scams.
- Protect your information: use strong passwords and enable two-factor authentication on your accounts to add an extra (12) ______ of security.
Choose a suitable word or phrase (marked A, B, C or D) to fill in each blank.
The unlucky cheater showed ______ used airline ticket but he was caught.
Cho hình thang \(A B C D\) vuông tại \(A\) và \(D\) có \(A B=6 a, A D=C D=\frac{1}{2} A B, M\) thuộc cạnh \(A D\) sao cho \(A M=\frac{1}{3} A D\). Tính \(T=(\overrightarrow{M B}+2 \overrightarrow{M C}) \cdot(\overrightarrow{C D}-\overrightarrow{B D})\).
Vì sao năm 1870, Phổ tiến hành cuộc chiến tranh với Pháp?
- Chọn phát biểu không phải là mệnh đề.
Công suất định mức của các dụng cụ điện là
\(\lim _{x \rightarrow 1^{+}} \frac{x+1}{x-1}\) bằng
Có mấy ứng dụng cơ giới hóa trong trồng trọt được giới thiệu?
Nội dung nào sau đây thể hiện đặc điểm pháp lí của doanh nghiệp?
Read the following leaflet and mark the letter A, B, C or D on your answer sheet to indicate the option that bestfits each of the numbered blanks from 7 to 12.
Sustainable Destinations
The new guide covers a range of sustainable travel options as well as sustainable hotels. All of them are (7) ________ and offer varying degrees of sustainable practices
Some suggested hotels:
Bettei Senjuan
Bettei Senjuan has a Green Key (8) ________ and is located at the foothills of Mount Tanigawa. A member of Relais & Châteaux luxury hotel group, the hotel has private open-air baths for each room, fed by flowing natural hot spring water.
Kuki
(9) ________ hotel option is Kuki, which is in the southwest of Hokkaido. The hotel is trying to reduce its carbon (10) ________ and waste. Water is heated through a natural hot spring to keep rooms warm and the food is from local producers. Kitchen waste is (11) ________compost for farms.
Zaborin
On the northern island of Hokkaido, Niseko Town was voted one of the world’s Top 100 Green Destinations in 2020 and 2021. This is where you will find content (12) ________ Zaborin, which incorporates modern, eco-friendly design and building techniques. Its walls are made out of recycled offcuts and an on-site hot spring provides carbon-neutral, underfloor heating in winter, and the cold spring water cools the building during the summer. Read the following leaflet and mark the letter A, B, C or D on your answer sheet to indicate the option that bestfits each of the numbered blanks from 7 to 12.
Sustainable Destinations
The new guide covers a range of sustainable travel options as well as sustainable hotels. All of them are (7) ________ and offer varying degrees of sustainable practices
Some suggested hotels:
Bettei Senjuan
Bettei Senjuan has a Green Key (8) ________ and is located at the foothills of Mount Tanigawa. A member of Relais & Châteaux luxury hotel group, the hotel has private open-air baths for each room, fed by flowing natural hot spring water.
Kuki
(9) ________ hotel option is Kuki, which is in the southwest of Hokkaido. The hotel is trying to reduce its carbon (10) ________ and waste. Water is heated through a natural hot spring to keep rooms warm and the food is from local producers. Kitchen waste is (11) ________compost for farms.
Zaborin
On the northern island of Hokkaido, Niseko Town was voted one of the world’s Top 100 Green Destinations in 2020 and 2021. This is where you will find content (12) ________ Zaborin, which incorporates modern, eco-friendly design and building techniques. Its walls are made out of recycled offcuts and an on-site hot spring provides carbon-neutral, underfloor heating in winter, and the cold spring water cools the building during the summer.
CHỦ ĐỀ 7
(Tham khảo bài văn của chủ đề trong đường link dưới đây ở trang 56)
https://tvsthpt.dlib.vn/app/doc-sach-ebook/d0a01a0e4114
Và trả lời câu hỏi sau:
Các chuỗi truyền điện tử (electron) nằm trên (…a…) ti thể. Khi điện tử được vận chuyển tử NADH tới oxygen sẽ đồng thời vận chuyển \({{\text{H}}^{+}}\) ngược gradien điện hoá vào không gian giữa hai màng làm cho nồng độ \({{\text{H}}^{+}}\) ở chất nền (…b…) so với không gian giữa hai màng.
Vị trí (a) là ________.
Theo quy định pháp luật, tình huống nào sau đây được ứng cử đại biểu Quốc hội và đại biểu Hội đồng nhân dân các cấp?
Nhân viên y tế đẩy xe bằng cáng với một lực có phương nằm ngang làm xe dịch chuyển theo hướng của lực. Khi đó, lực đẩy xe đã
Điểm giống nhau giữa mô hình chăn nuôi bền vững và chăn nuôi thông minh.
