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Problems Caused by Using Computers

Long hours at the screen can cause     41    (ache) eyes,     42   (blur) vision and headaches,  experts say. In fact, eyestrain surpasses even wrist pain as the top physical  ___43__ (complain) among heavy computer users. When peering into the computer screen, the eye's focusing muscle is at constant tension. Like any muscle, it feels sore when  ____44___(overload) . And when someone spends a lot of time looking at something close, the eye muscle can get  ____45___(stick) on the near-focus setting and have difficulty relaxing, leaving the person    46    (temporary) nearsighted, a condition called accommodative spasm (痉挛) that can last seconds or hours. The letters on the screen are not as clearly  ____47___(define) as on a printed page. Take a magnifying glass to your monitor and you'll see the letters. each made up of pinpoint sources of light, have no sharp edges. But those liquid crystal display (LCD) monitors, like those found on laptop computers, are    48    (easy) on the eyes be-cause they display sharper images. And studies have shown that when people are working on a computer, their rate of  ____49___ (blink) goes down by two-thirds, which can result in dry, stinging eyes. This is especially a problem for contact-lenses    50    (wear) . 

Now doctors can successfully cure stomach ulcers.

• A、True
  
  

• B、False
  
  

• C、Not Given
  
  

Task 2

21. The machinery outside the calorimeters records everything________

22. Nicola Waiters had time for the experiments________

23. Volunteers have to get prepared for the time in the calorimeter________

24. The experiments show that high-fat diets________

25. It seems Nicola will continue________

A. the volunteers do

B. to support their further sessions of experiment

C. because the life there can be very boring

D. make people overeat

E. because she was her own boss

F. after passing a high-protein test