Câu hỏi: Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 30 to 34.
Why is it that flying to New York from London will leave you feeling less tired than flying to London from New York? The answer may be a clear case of biology not being able to keep up with technology. Deep inside the brain there is a "clock" that governs every aspect of the body's functioning: sleep and wake cycles, levels of alertness, performance, mood, hormone levels, digestion, body temperature and so on. It regulates all of these functions on a 24-hour basis and is called the circadian clock (from the Latin, circa "about" + dies "day").
This body clock programmes us to be sleepy twice a day, between 3-5 a.m and again between 3-5 p.m. Afternoon tea and siesta times are all cultural responses to our natural biological sleepiness in the afternoon. One of the major causes of the travelers' malady known as jet lag is the non-alignment of a person's internal body clock with clocks in the external world. Crossing different time zones confuses the circadian clock, which then has to adjust to the new time and patterns of light and activity. To make matters more complex, not all internal body functions adjust at the same rate. So your sleep/wake may adjust to a new time zone at one rate, while your temperature adjusts at a different pace. Your digestion may be on a different schedule altogether.
Though we live in a 24-hour day, the natural tendency of the body clock is to extend our day beyond 24 hours. It is contrary to our biological programming to shrink our day. That is why travelling in a westward direction is more body-clock friendly than flying east. NASA studies of long haul pilots showed that westward travel was associated with significantly better sleep quantity and quality than eastward flights. When flying west, you are "extending" your day, thus travelling in the natural direction of your internal clock. Flying eastward will involve "shrinking" or reducing your day and is in direct opposition to your internal clock's natural tendency.
One of the more common complaints of travelers is that their sleep becomes disrupted. There are many reasons for this: Changing time zones and schedules, changing light and activity levels, trying to sleep when your body clock is programmed to be awake, disruption of the internal circadian clock and working longer hours. Sleep loss, jet lag and fatigue can seriously affect our ability to function well. Judgment and decision-making can be reduced by 50%, attention by 75 percent, memory by 20 percent and communication by 30 percent. It is often suggested that you adjust your watch as soon as you board a plane, supposedly to try to help you adjust to your destination's schedule as soon as you arrive. But it can take the body clock several days to several weeks to fully adjust to a new time zone.
Jet lag ______________.
A. makes our body clock operate badly
B. causes our body clock to change
C. extends the hours of our body clock
D. upsets our body's rhythms
Why is it that flying to New York from London will leave you feeling less tired than flying to London from New York? The answer may be a clear case of biology not being able to keep up with technology. Deep inside the brain there is a "clock" that governs every aspect of the body's functioning: sleep and wake cycles, levels of alertness, performance, mood, hormone levels, digestion, body temperature and so on. It regulates all of these functions on a 24-hour basis and is called the circadian clock (from the Latin, circa "about" + dies "day").
This body clock programmes us to be sleepy twice a day, between 3-5 a.m and again between 3-5 p.m. Afternoon tea and siesta times are all cultural responses to our natural biological sleepiness in the afternoon. One of the major causes of the travelers' malady known as jet lag is the non-alignment of a person's internal body clock with clocks in the external world. Crossing different time zones confuses the circadian clock, which then has to adjust to the new time and patterns of light and activity. To make matters more complex, not all internal body functions adjust at the same rate. So your sleep/wake may adjust to a new time zone at one rate, while your temperature adjusts at a different pace. Your digestion may be on a different schedule altogether.
Though we live in a 24-hour day, the natural tendency of the body clock is to extend our day beyond 24 hours. It is contrary to our biological programming to shrink our day. That is why travelling in a westward direction is more body-clock friendly than flying east. NASA studies of long haul pilots showed that westward travel was associated with significantly better sleep quantity and quality than eastward flights. When flying west, you are "extending" your day, thus travelling in the natural direction of your internal clock. Flying eastward will involve "shrinking" or reducing your day and is in direct opposition to your internal clock's natural tendency.
One of the more common complaints of travelers is that their sleep becomes disrupted. There are many reasons for this: Changing time zones and schedules, changing light and activity levels, trying to sleep when your body clock is programmed to be awake, disruption of the internal circadian clock and working longer hours. Sleep loss, jet lag and fatigue can seriously affect our ability to function well. Judgment and decision-making can be reduced by 50%, attention by 75 percent, memory by 20 percent and communication by 30 percent. It is often suggested that you adjust your watch as soon as you board a plane, supposedly to try to help you adjust to your destination's schedule as soon as you arrive. But it can take the body clock several days to several weeks to fully adjust to a new time zone.
Jet lag ______________.
A. makes our body clock operate badly
B. causes our body clock to change
C. extends the hours of our body clock
D. upsets our body's rhythms
Dẫn chứng: Crossing different time zones confuses the circadian clock, which then has to adjust to the new time and patterns of light and activity. To make matters more complex, not all internal body functions adjust at the same rate. So your sleep/wake may adjust to a new time zone at one rate, while your temperature adjusts at a different pace. Your digestion may be on a different schedule altogether. (Qua những múi giờ khác nhau làm xáo trộn đồng hồ sinh học, mà sau đó phải điều chỉnh thời gian mới và ánh sáng và hoạt động. Để làm cho vấn đề phức tạp hơn, không phải tất cả các chức năng bên trong cơ thể điều chỉnh ở mức tương tự. Vì vậy, giấc ngủ/ sự tỉnh giấc của bạn có thể điều chỉnh đến một múi giờ mới ở một tốc độ, trong khi nhiệt độ tự điều chỉnh với một tốc độ khác. Sự tiêu hóa của bạn có thể ở trên một thời gian biểu khác hoàn toàn.)
Đáp án B.