Một vật dao động điều hòa với phương trình $x=8\cos\left(4\pi t-\dfrac{\pi}{3}\right)$ (cm). Khoảng thời gian để vật thực hiện được 1 dao động toàn phần là

Chọn một từ mà nghĩa của nó KHÔNG cùng nhóm với các từ còn lại.

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.

ANNOUNCEMENT OF SCHOOL SPORTS DAY

The School Athletics Department is pleased ___(7)___:

● All athletes ___(8)___ to report at the school field by 08:00 AM on June 10.

● Each team must prepare and submit their entry list for each event. Each athlete is allowed to participate ___(9)___ three events.

● The school will ___(10)___ trophies and medals for the winners in each category.

● ___(11)___ you have any inquiries regarding the event schedule or rules, please contact the Athletics Department.

Typically, all the sports ___(12)___ are concluded by an award ceremony. After finishing all the activities, custom awards, incentives, and more should be given to appreciate the competitors and encourage them to improve.

Nguyên tử X có 3 lớp electron, trong đó lớp ngoài cùng có chứa 5 electron. X có điện tích hạt nhân là

Cho tứ diện ABCD có độ dài các cạnh \(A B=A C=A D=B C=B D=a\) và \(C D=a \sqrt{2}\). Tính góc giữa hai đường thẳng AD và BC.

Trong các tiền đề sau đây, tiền đề nào là quan trọng nhất dẫn đến cách mạng bùng nổ và thắng lợi ở Nga năm 1917?

Trong các thế kỉ XVI – XVIII, ở các nước Âu – Mỹ, phương thức sản xuất tư bản chủ nghĩa phát triển nhất trong lĩnh vực

Read the following passage about education in Nepal 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. 

A few years ago, amid a record drought, scientists noticed something odd. A few of California’s giant sequoias inside Sequoia and Kings Canyon National Parks were dying in ways no one had ever documented – from the top down. When researchers climbed into the canopies, they discovered that beetles had bored into a few branches. By 2019, at least 38 of the trees had died – not a large number, but "concerning because we’ve never observed this before,” says Christy Brigham, the park’s chief of resource management.

Scientists had assumed that stately sequoias, with their bug-repelling tannins, were immune to dangerous pests. Worried experts are investigating whether some mix of increased drought and wildfire, both worsened by climate change, have now made even sequoias susceptible to deadly insect invasions.

If so, these ancient sentinels would be just the latest example of a trend experts are documenting around the world: Trees in forests are dying at increasingly high rates—especially the bigger, older trees. According to a study in the journal Science, the death rate is making forests younger, threatening biodiversity, eliminating important plant and animal habitat, and reducing forests’ ability to store excess carbon dioxide generated by our consumption of fossil fuels. [A]

There is no single direct cause. Decades of logging and land clearing play a role, scientists say. But increasing temperatures and rising carbon dioxide from the burning of fossil fuels have significantly magnified most other causes of tree death. Scientists are documenting longer and harsher droughts, more severe outbreaks of insects and disease, and increasingly catastrophic wildfires.

With 60,000 known tree species on Earth, those shifts are playing out differently across the planet. In central Europe, for instance, “You don’t have to look for dead trees,” says Henrik Hartmann, with Germany's Max Planck Institute for Biogeochemistry. “They’re everywhere.” In one recent year, following a week of excessive heat, hundreds of thousands of beech trees dropped their leaves. Even in colder regions, “You get a couple of hot years and the forests are suffering,” says Hartmann. “There are individual species that are being driven beyond the threshold of what they can handle.” [B]

Just last year, massive fires marched through a dry Australia, smoldered across 7.4 million acres in northern Siberia, and focused the world’s attention on blazes in the Amazon.

The consequences of all these changes around the world are still being assessed. The first national look at tree mortality in Israel showed vast stretches disappearing, thanks largely to scorching heat and wildfires. [C] In a country largely blanketed by stone and sand, forests mean a great deal. Trees support nests for eagles and habitat for wolves and jackals. They hold soil with their roots. [D]

“We’re dealing with a very tough situation. It’s a race to the unknown,” says Tamir Klein at the Weizmann Institute of Science.

In which space (marked A, B, C and D in the passage) will the following sentence fit?

Without them, plants that normally rise in trees’ shadows are suddenly exposed to higher temperatures and bright light.

Theo em, khi vay tín chấp, người vay cần có trách nhiệm nào sau đây?

Read the following passage about Unconventional Teachers Who Changed Lives 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.

Traditional education focuses on textbooks, but some teachers go beyond these limitations. Mrs. Rodriguez transformed her classroom into a living laboratory. Her students conducted experiments with plants and simple machines. She believed hands-on learning creates deeper understanding than reading alone. When asked why she taught differently, she replied, "I want students to fall in love with discovery." Her methods helped struggling students improve and develop passion for science.

Mr. Jackson abandoned lectures for storytelling and role-playing. His students experienced history by acting out important moments. This approach made history come alive and helped them remember key information. One student said, "Before Mr. Jackson's class, I thought history was boring, but he showed us it's fascinating." He took classes to historical sites and invited veterans to share experiences. These connections helped students understand how past shapes our present.

In a remote village, Ms. Chen taught English without proper textbooks. She created materials using newspapers and song lyrics. Despite limited resources, her students achieved remarkable results through her dedication. "Learning should be joyful, not painful," she told questioning parents. Ms. Chen organized conversation clubs and pen pal exchanges. These activities gave students practical language skills and confidence to use English in real situations.

Coach Williams was a life mentor who taught valuable lessons through sports. He focused on teamwork and fair play rather than winning. Students who struggled academically often excelled in his class. "The playing field is where children learn who they truly are," he explained. He created inclusive activities for all students regardless of athletic ability. Many former students credit him with teaching life skills like resilience and cooperation that helped them succeed after graduation.

Which of the following is TRUE according to the passage?

Cho một cấp số cộng có \({{u}_{1}}=-3;\,{{u}_{6}}=27\). Công sai của cấp số cộng là

Để giảm thiểu phát thải các khí nhà kính, Hoa Kì chú ý biện pháp gì?

Trong không gian $O x y z$, cho vectơ $\overrightarrow{a}=2 \overrightarrow{i}+\overrightarrow{j}-2 \overrightarrow{k}$. Độ dài của vectơ $\overrightarrow{a}$ bằng

Đọc đoạn trích sau:

“Thường thì đến gà gáy sáng Mị ngồi dậy ra bếp sưởi một lúc thật lâu thì các chị em trong nhà mới bắt đầu dậy ra dóm lò bung ngô, nấu cháo lợn. Chỉ chợp mắt được từng lúc, Mị lại thức sưởi lửa suốt đêm. Mỗi đêm, khi nghe tiếng phù phù thổi bếp, A Phủ lại mở mắt. Ngọn lửa sưởi bùng lên, cùng lúc ấy thì Mị cũng nhìn sang, thấy mắt A Phủ trừng trừng, mới biết A Phủ còn sống. Mấy đêm nay như thế. Nhưng Mị vẫn thản nhiên thổi lửa, hơ tay. Nếu A Phủ là cái xác chết đứng đấy, cũng thế thôi. Mị vẫn trở dậy, vẫn sưởi, chỉ biết chỉ còn ở với ngọn lửa. Có đêm A Sử chợt về, thấy Mị ngồi đấy, A Sử đánh Mị ngã ngay xuống cửa bếp. Nhưng đêm sau Mị vẫn ra sưởi như đêm trước. ”

(Tô Hoài, Vợ chồng A Phủ, Ngữ văn 12, tập hai, NXB Giáo dục Việt Nam, 2014)

Văn bản trên đã sử dụng phương thức biểu đạt chính nào?