Trên sợi dây có chiều dài l, hai đầu cố định, đang có sóng dừng. Trên dây có một bụng sóng. Biết tốc độ truyền sóng trên dây là $v$ không đối. Tần số của sóng là

Nước ta, diện tích đồi núi trọc ngày càng tăng ở vùng núi, hoang mạc hóa diễn ra mạnh ở vùng ven biển là do đâu?

Một vật dao động điều hòa khi đang chuyển động từ vị trí cân bằng đến vị trí biên âm thì

Thao tác nào sau đây được dùng để kiểm tra kết quả sau khi kết nối các bộ phận của máy tính?

Ở chim, hô hấp nhờ phổi và hệ thống túi khí nên

Từ lâu, Liên bang Nga đã được coi là cường quốc về ngành công nghiệp 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?

Pha sáng của quá trình quang hợp diễn ra ở đâu?

Read the following passage about studying abroad 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.

Successful students often do the followings while studying. First, they have an overview before reading. Next, they look for important information and pay greater attention to it (which often needs jumping forward or backward to process information). They also relate important points to one another. Also, they activate and use their prior knowledge. When they realize that their understanding is not good, they do not wait to change strategies. Last, they can monitor understanding and take action to correct or “fix up” mistakes in comprehension.

Conversely, students with low academic achievement often demonstrate ineffective study skills. [I] They tend to assume a passive role in learning and rely on others (e.g., teachers, parents) to monitor their studying. [II] For example, low-achieving students often do not monitor their understanding of content; they may not be aware of the purpose of studying; and they show little evidence of looking back or employing “fix-up” strategies to fix understanding problems. [III] Students who struggle with learning new information seem to be unaware that they must extend effort beyond simply reading the content to understand and remember it. [IV] 

Children with learning disabilities do not plan and judge the quality of their studying. Their studying may be disorganized. Students with learning problems face challenges with personal organization as well. They often have difficulty keeping track of materials and assignments, following directions, and completing work on time. Unlike good studiers who employ a variety of study skills in a flexible yet purposeful manner, low-achieving students use a restricted range of study skills. They cannot explain why good study strategies are important for learning; and they tend to use the same, often ineffective study approach for all learning tasks, ignoring task content, structure or difficulty.

Which of the following best paraphrases the underlined sentence in paragraph 2:  

Cho hàm số $y=\ln \left(x^4+1\right)$. Khi đó $y^{\text{'}}\left(1\right)$ có giá trị bằng?

Con hãy lựa chọn đáp án Đúng hoặc Sai

“Phương pháp kí hiệu đường chuyển động biểu hiện các đối tượng địa lí đứng yên trong không gian như các loại gió, dòng biển, các luồng di dân, ...”

Đúng

Sai

Read the following passage about The Longitude Prize and mark the letter A, B, C, or D on your answer sheet to indicate the best answer to each of the following questions

     On a stormy night in 1707, four ships struck rocks off the south coast of England and sank. [I] One thousand, four hundred sailors were drowned. [II] The ships had crashed because they had no way of knowing how far they had travelled in a particular direction; they could not calculate their longitude, which required accurate time measurement. [III] In such difficult circumstances, they believed that the best response to the disaster was a competition: the Longitude Prize. [IV]

     The Longitude Prize was no ordinary competition. To win it, someone had to find a way of calculating how far a ship had travelled east or west from its point of departure. Geniuses such as Sir Isaac Newton had failed to find a solution, so to ensure the interest of Britain’s greatest scientific minds, the government offered a prize of £20,000 — the equivalent of £2.6 million in today’s money. But to everyone’s surprise, it wasn’t a famous academic who solved the problem, but an unknown carpenter.

     When John Harrison wasn’t working with wood, he was making clocks. An accurate clock would allow sailors to calculate their position, but at the time it was thought impossible to create a mechanical clock that could work on a ship. The movement of the sea and the changes in temperature destroyed the delicate parts. However, after three frustrated attempts, Harrison’s fourth sea clock, H4, finally triumphed. Its mechanics were so good that the H4 worked better than most clocks on land.

   The Longitude Prize and Harrison’s success generated a lot of interest in the 18th century, but it was soon forgotten. However, in 2013, the British government created a new Longitude Prize, offering £10 million to the person who could solve a great challenge to humanity. An enthralled public then took part in a TV programme where viewers chose one challenge from a list of six for scientists to focus on. The question now is, will someone be able to solve it just as well as Harrison solved the challenge presented to him?

Which of the following best summarises paragraph 3?

Dưới đây là hình ảnh liên quan đến cuộc cách mạng công nghiệp. Hãy cho biết đâu là công nghệ thông tin và động cơ hơi nước?

Humans now have to suffer the effects of global warming due to having treat the environment irresponsibly.

Thảm thực vật tiêu biểu ở khu vực Mỹ La tinh là

 Chị C là nội trợ thường xuyên đi siêu thị để mua thực phẩm và các đồ gia dụng trong nhà. Trong trường hợp này chi C đóng vai trò là chủ thể gì của nền kinh tế?

Phản ứng tổng hợp ammonia:

N2(g) + 3H2(g) → 2NH3(g)            \({{\text{ }\!\!\Delta\!\!\text{ }}_{r}}\text{H}_{\text{298}}^{\text{o}}=-92\text{ }\!\!~\!\!\text{ }kJ\)

Biết năng lượng liên kết (kJ/mol) của N ≡ N và H – H lần lượt là 946 và 436. Năng lượng liên kết của N−H trong ammonia là

Sau khi chiếm được 3 tỉnh miền Đông Nam Kỳ, thực dân Pháp gặp nhiều khó khăn trong việc tổ chức, quản lý những vùng đất mới chiếm được do 

Cho m gam kim loại Na tác dụng với dung dịch HCl dư. Sau phản ứng thu được 6,72 lít H₂ (đktc). Giá trị  m là