Một vật dao động điều hòa với phương trình $x=5\cos6\pi\left(\dfrac{t}{2}-\dfrac{1}{12}\right)$ ($x$ tính bằng cm, $t$ tính bằng s). Chu kì dao động của vật xấp xỉ là

Cho biết: Virus nào gây ra bệnh Pox nhỏ?

Hai nguồn kết hợp là hai nguồn có

Các chất thải sinh ra từ quá trình trao đổi chất được vận chuyển vào yếu tố nào?

Tập nghiệm của bất phương trình ${{2}^{x}} \le 4$ là

Rewrite the following sentences without changing their meaning, using the given words. Write full sentence.

Her hair needs cutting.

She needs ___________________.

Một chất điểm dao động điều hoà với phương trình . Li độ của chất điểm khi pha dao động bằng là

Một hạt nhân có 8 proton và 9 neutron. Năng lượng liên kết riêng của hạt nhân này bằng 7,75 MeV/nucleon. Biết m_p = 1,0073 amu, m_n = 1,0087 amu. Khối lượng của hạt nhân đó bằng bao nhiêu amu?

Mark the letter A, B, C or D to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.

Một phân tử DNA có chiều dài 5100 Å, trong đó số nucleotide loài A gấp hai lần số nucleotide loại G. Biết rằng, mỗi nucleotide có chiều dài là 3,4 Å. Số lượng nucleotide loại C của phân tử DNA là

Phương trình \(2{x^2} - 6x + 4 = 3\sqrt {{x^3} + 8} \) có hai nghiệm dạng \(x = a \pm b\sqrt {13} \) với \(a,b \in \mathbb{N}\). Tính \({a^2} - b\)?

Mầm bệnh của bệnh tụ huyết trùng trâu bò là

Read the following passage about Asia’s culture and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions

[I] Chemicals are present everywhere in our environment, some of which occur naturally, while others are the result of human activities. [II]. They are found in the air, water, and soil, and can have both positive and negative impacts on the ecosystem. Some chemicals, like nutrients, help support life by promoting plant growth [III]. However, others, especially synthetic chemicals such as pesticides, fertilizers, and industrial waste, can be harmful to both the environment and human health. [IV]

The widespread use of pesticides and fertilizers in agriculture has been a major cause of chemical pollution. When these chemicals are used improperly or excessively, they can wash into rivers, lakes, and oceans, leading to water pollution. This runoff can also contribute to the depletion of oxygen in water bodies, a process known as eutrophication. Eutrophication harms aquatic life, disrupting ecosystems and causing the death of fish and other organisms that rely on oxygen.

Toxic chemicals such as heavy metals (e.g., mercury and lead) pose additional threats to the environment and human health. These substances can accumulate in the food chain, starting from plants and animals in contaminated areas and eventually reaching humans. Long-term exposure to these chemicals can lead to serious health issues, including neurological disorders, cancer, and other chronic conditions. Many countries have established regulations to limit the use of harmful chemicals, but enforcement remains a challenge.

Efforts to reduce chemical pollution involve a combination of government regulations, technological innovations, and public awareness. Governments worldwide have introduced stricter rules on the use of hazardous chemicals and encouraged the development of eco-friendly alternatives. These regulations aim to limit the harmful impact of chemicals on the environment, encouraging industries to adopt safer practices. Environmental organizations play a vital role in monitoring chemical pollution, raising awareness, and advocating for cleaner technologies. They work closely with policymakers to ensure effective enforcement of environmental laws. While progress has been made, ongoing efforts are needed to address emerging challenges and ensure a safer and healthier environment for future generations.

Which of the following best paraphrases the underlined sentence in paragraph III?

"These substances can accumulate in the food chain, starting from plants and animals in contaminated areas and eventually reaching humans."