A
Knowing which of these statements have been proved by SCIENCE — and which are MYTHS(谬论) — could improve your health. Here are some health facts your doctor wants you to know.
Not all heart attacks have a symptom of chest pain.
Truth! A 2012 study of more than 1.1 million heart attack patients found that 31 percent of men and 42 percent of women didn’t have any chest pain before being hospitalized. Call 911 for other symptoms, too, including shortness of breath, light- headedness, and pain elsewhere in the upper body.
You do not need eight glasses of water every day.
Truth! There is not any scientific evidence that eight is the magic number. You might need more or less than that, depending on factors such as climate and body size. To make sure you are getting enough, just drink water throughout the day.
You need less sleep as you get older.
Myth! Older adults often sleep less as a result of serious conditions that are more common with age as well as the drugs used to treat them. But that doesn’t mean they require less sleep. While sleep needs vary from person to person, most adults should get at least seven hours of sleep for health.
Reading in dim light will harm your eyes.
Myth! It might tire your eyes in the short term, but there’s no evidence that it will do any lasting damage. When reading, position light to shine directly on the page rather than from over your shoulder to reduce unpleasant bright light.
21. Which of the following has been proved to be true?
A. You are in need of much less sleep as you get older.
B. Reading in dim light does lasting damage to your eyes.
C. Some heart attacks don’t have a symptom of chest pain.
D. You must get more than eight glasses of water every day.
22. According to the text, what may be the result of using drugs?
A. Heart attacks. B. Weak eyes.
C. Less sleep. D. Shortness of breath.
23. What’s the purpose of the text?
A. To inform. B. To entertain. C. To advertise. D. To praise.
