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 39 to 43.

Everyone knows that good sleep is vitally important for our health. Not everyone knows how important it is to sleep in the dark. A new report says that sleeping with the light on could be bad for our health. Researchers say that turning off the light when we sleep helps to keep away diabetes and heart diseases. Sleeping with thelight on could increase the risk of getting these diseases. The researchers said that around 40 percent of people sleep with some sort of artificial light. They said even the light from a television or alarm clock could affect our health. They added that the worst thing to sleep with is a main light. Sleeping in the dark is more difficult for people who live in cities where there is a lot of outdoor light at night.

The researchers are from the Northwestern University Feinberg School of Medicine in Chicago, USA. Dr Phyllis Zee, who is an expert in sleep medicine, is the lead researcher. She said that it is healthier for us to turn off all lights when we sleep. Her team conducted a study of the blood sugar levels of 20 people after nights of sleep. The people who slept with a light on had higher blood sugar levels the next morning compared to those who slept in total darkness. Dr. Zee said this is because light stimulates brain activity, which raises blood sugar levels. She said there are three things we can do to reduce the risk of illness. The first thing is we should turn off the lights. Moreover, we should never sleep with white or blue light. Finally, it is a good idea to use a blackout curtain or wear an eye mask.

According to the passage, why do people who live in cities find sleeping in the dark difficult?

Đáp án đúng là: C
Giải thích
Kiến thức: Đọc – Chi tiết
Giải thích: Theo đoạn văn, tại sao những người sống ở thành phố thấy khó ngủ trong bóng tối? A. Bởi vì tất cả mọi người ở các thành phố không bao giờ tắt đèn khi đi ngủ.
B. Bởi vì họ ngủ với ánh sáng nhân tạo, chẳng hạn như tivi.
C. Vì ban đêm ở các thành phố có nhiều ánh sáng ngoài trời.
D. Bởi vì những người ở thành phố thích ngủ với ánh sáng trắng hoặc xanh.
Thông tin: Sleeping in the dark is more difficult for people who live in cities where there is a lot of outdoor
light at night.
Tạm dịch: Ngủ trong bóng tối khó khăn hơn đối với những người sống ở thành phố nơi có nhiều ánh sáng
ngoài trời vào ban đêm.