Ở kì nào của động cơ Diesel 4 kì, xu páp thải đóng?

Cơ chế thị trường tự điều chỉnh tuân theo yêu cầu của các quy luật kinh tế nào?

Người Bồ Đào Nha, Anh, Pháp, Hà Lan đến nước ta để mang hàng hóa của họ đổi lấy những gì?

Cho 2 điện tích điểm nằm ở 2 điểm A và B và có cùng độ lớn, cùng dấu. Cường độ điện trường tại một điểm trên đường trung trực của AB thì có phương

Một bộ acquy có thể cung cấp dòng điện 4A liên tục trong 2 giờ thì phải nạp lại. Tính cường độ dòng điện mà acquy này có thể cung cấp liên tục trong 40 giờ thì phải nạp lại.

Số lượng hàng hóa và dịch vụ mà nhà cung cấp sẵn sàng đáp ứng cho nhu cầu thị trường với mức giá được xác định trong khoảng thời gian nhất định được gọi là gì?

Chọn ý đúng nhất: Đặc điểm nào không đúng với ngành nội thương ?

Các dạng địa hình nào chiếm phần lớn diện tích khu vực Mỹ Latinh?

Sự khác biệt giữa mạng LAN và Internet thể hiện ở yếu tố nào sau đây?

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?

According to paragraph 4, which of the following is NOT a problem that arose from using mechanical clocks on ships?

Chủ tịch nước có vị trí như thế nào trong bộ máy nhà nước Việt Nam?

Biết I_o là cường độ âm chuẩn. Tại điểm có cường độ âm I thì mức cường độ âm là

Hiện nay, dân số Hoa Kì đứng thứ mấy trên thế giới?

Các yếu tố cấu thành thị trường gồm những thành phần nào?

Công suất tiêu thụ năng lượng điện của đoạn mạch được tính bằng?

Không khí trong đất cung cấp O₂ cho:

Mệnh đề nào sau đây đúng?

Chọn từ thích hợp điền vào chỗ chấm để hoàn thiện khái niệm sau:

“…… là sự tiến bộ về vật chất và tinh thần của xã hội loài người; là trạng thái phát triển cao của nền văn hóa, khi xã hội loài người vượt quan trình độ của thời kì dã man”.

Tập xác định của hàm số \(y=\frac{1}{\text{sin}x-\text{cos}x}\) là

Read the passage below and choose A, B, C or D.

Although noise, commonly defined as unwanted sound, is a widely recognized form of pollution, it is very difficult to measure because the discomfort experienced by different individuals is highly subjective and, therefore, variable. Exposure to lower levels of noise may be slightly irritating, whereas exposure to higher levels may actually cause hearing loss. Particularly in congested urban areas, the noise produced as a by-product of our advancing technology causes physical and psychological harm, and detracts from the quality of life for those who are exposed to it.

Unlike the eyes, which can be covered by the eyelids against strong light, the ear has no lid, and is, therefore, always open and vulnerable; noise penetrates without protection. Noise causes effects that the hearer cannot control and to which the body never becomes  accustomed. Loud noises instinctively signal danger to any organism with a hearing mechanism, including human beings. In response, heartbeat and respiration accelerate, blood vessels constrict, the skin pales, and muscles tense. In fact, there is a general increase in functioning brought about by the flow of adrenaline released in response to fear, and some of these responses persist even longer than the noise, occasionally as long as thirty minutes after the sound has ceased.

Because noise is unavoidable in a complex, industrial society, we are constantly responding in the same way that we would respond to danger. Recently, researchers have concluded that noise and our response may be much more than an annoyance. It may be a serious threat to physical and psychological health and well-being, causing damage not only to the ear and brain but also to the heart and stomach. We have long known that hearing loss is America's number one nonfatal health problem, but now we are learning that some of us with heart disease and ulcers may be victims of noise as well. Fetuses exposed to noise tend to be overactive, they cry easily, and they are more sensitive to gastrointestinal problems after birth. In addition, the psychic effect of noise is very important. Nervousness, irritability, tension, and anxiety increase affecting the quality of rest during sleep, and the efficiency of activities during waking hours, as well as the way that we interact with each other.

What does the word “it” in paragraph 1 refer to?