Hệ nào sau đây có thể coi tương đương như một tụ điện?

Theo em cho bài toán tính tổng s=1+2+3+...+n. Để giải bài toán trên ta có thể dùng:

Read the following passage about home schooling in the UK 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.

Full-time education in the UK is compulsory from the age of five to sixteen, but this doesn’t have to be in a school. Around 50,000 children are educated at home. This is called ‘homeschooling’.

 Parents take their children out of school for different reasons, like illness and the need for special care, or because the distance to the nearest school may be too far. Some children are simply unhappy at school. Whatever the reason, they’re allowed to study at home, although inspectors regularly check how they are getting on.

 Hayley and Jenny haven’t been to school for two years but they haven’t neglected their studies. Their mother worked out strict timetables for them, with hourly lessons for each day. She’s responsible for teaching them Maths, English, History and French. Their father teaches them Science and Geography. They study all the other school subjects online. ‘We have lessons with Dad in the evenings and at weekends,’ explains Hayley.

 The family’s home is in a remote part of Wales. ‘The girls were fine at school but they spent so much time getting to school, they were too tired to learn, says their mother, Julia”. ‘We had a family conference and in the end we decided to try homeschooling. So far, it’s been a big success, but the girls know that if they want to go back to school at any time, we’ll let them. We follow the normal school program of lessons, and they will take all the normal school exams.’

 There are disadvantages too, of course. ‘Social isolation is something I worry about,’ says Julia. They both seem happy and well-adjusted, but they haven’t really got friends who live locally. But in the summer holidays they go away on trips to summer camps, where they have no trouble mixing with people and making friends.’

Which of the following is TRUE according to the passage?

Vì sao nhà nước ta phải thu thuế gián thu?

Đoạn trích bao gồm những sự kiện chính nào?

In paragraph 1, the word "room” is closest in meaning to ____.

Nội dung nào sau đây thuộc nội dung cơ bản về khoa học, công nghệ và môi trường của Hiến pháp?

Bản vẽ thiết kế phương án:

Cho phản ứng: \(\mathrm{H}_{2} \mathrm{O}+\mathrm{Br}_{2} \rightarrow \mathrm{HOBr}+\mathrm{HBr}\)

Phát biểu nào sau đây về bromine trong phản ứng trên là đúng?

Planting trees can contribute to reducing global warming.

Trong các thiết bị dưới, thiết bị nào là thiết bị thông minh?

Đảo nào nằm ở phía Bắc của Nhật Bản?

Nguồn lực tài nguyên thiên nhiên được coi là nhân tố như thế nào?

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.

Working on Your Workout

(I) Although appreciating a balanced diet and regular exercise, most people do not know how to exercise properly. Consequently, they usually rush through their workouts, or they make the same common workout mistakes. (II) Exercising the right way is important for people who are worried about their health and their appearance. (III) However, if someone is not working out properly, they will not see the results they want. Therefore, training experts have devised tips to teach people how to exercise correctly in order to achieve the greatest health benefits. (VI)

One of the most common workout mistakes is doing the same routine over and over again. This does not challenge your muscles, and it can actually prevent muscles from growing and repairing themselves. Instead of always sticking to the same old workout, it is important to change your routine every six to eight weeks. It is also important to add a variety of workouts to your routine, such as swimming, yoga, or biking, to make sure your whole body stays fit. This will help make your workouts more interesting, and benefit your health and muscle development as well.

Another mistake people tend to make is to work out too hard, too often. Your body needs to rest between workouts; otherwise, no progress will be made. It is best to keep the number of hard workout routines to no more than two per week. Then, for those who don’t want to get off schedule by skipping a day, shorter workouts of about twenty minutes can be used on other days. For more variety in workouts, you could also plan an easier routine for forty to sixty minutes between days of shorter, more intense workouts. Experts recommend, however, taking at least one day off completely each week, especially after several hard workout days in a row.

In reality, no one is perfect. However, if you want to make a difference in your overall health, there are some things you can do. Stretch before and after every workout. Do not rush your routine, and do not work out too little or too much. Remember not to make these common workout mistakes, and always have fun while exercising!

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

Đọc đoạn trích và trả lời câu hỏi dưới đây.

Phiên âm:

Tẩu lộ tài tri tẩu lộ nan

Trùng san chi ngoại hựu trùng san

Trùng san đăng đáo cao phong hậu

Vạn lý dư đồ cố miện gian.

Dịch thơ:

Đi đường mới biết gian lao,

Núi cao rồi lại núi cao trập trùng;

Núi cao lên đến tận cùng,

Thu vào tầm mắt muôn trùng nước non.

(Hồ Chí Minh, Đi đường, in trong Nhật kí trong tù, Hồ Chí Minh toàn tập, NXB Chính trị Quốc gia, Hà Nội, 2002)

Có thể thay thế từ “gian lao” trong bản dịch bài thơ “Đi đường” bằng từ nào?

Biết nhiệt hóa hơi riêng của thủy ngân là 2,96.10⁵ J/kg. Nhiệt lượng cần để làm bay hơi hoàn toàn 2 kg thủy ngân là