Some say it is evident that computers can damage a person’s eyesight. Since the popularity of computers began to skyrocket, there have been questions _1_ with computer screens and eye strain. There are plenty of symptoms that often show up as a result of eye strain from computer screens. It may first start with a little _2_. Then, it may progress to dry eyes, _3_ vision and even headaches. However, the extent to which computer screens damage eyesight is _4_ unclear.
Taking a ten to 15 minutes' break every hour while working is a good way to help avoid this and rest your eyes, though your _5_ may not be as generous with your break periods. If possible, break up computer tasks and non-computer tasks throughout the day as much as possible.
One of the major improvements in computer screens has also helped Still, even an LCD screen, if it is not adjusted _6_ or if it is too bright, can be just as hard on the eyes. This is very important as many people tend to keep their LCD screens too bright, simply because they are not viewing them from a proper angle and may be trying to _7_ for the “screen door” effect.
Fortunately, most of the eye damage, if it is to be called that, resulting from the use of computer
screens tends to be a __8__ situation. Once the eyes are rested long enough, the symptoms tend to quickly go away. However, if the eyes are not _9_ rested, the symptoms may return quicker than they appeared at first once computer activities _10_.
A) somewhat B) principal C) temporary D) vulnerable
E) soreness F) properly G) sufficiently H) whereby
I) compensate J) employers K) associated L) prospect
M) blurred N) proceeded O) resume
1.[K] ... with computer screens and eye strain作后置定语，修饰名词questions,因此空格处应填入动词分词，且能与with搭配。词库中associated符合句意，指这些问题把电脑屏幕和眼睛疲劳“联系”起来。
3.[M]空格后是名词，且与前面的dry eyes为并列关系，由此可见空格处最有可能是形容词，说明视觉疲劳对视力的影响，分词blurred符合句意,blurred vision意为“视觉模糊”。
9.[G] however表明此句与上句形成对比，上句讲的是得到足够的休息(rested long enough),由此可知，本句讲的是休息不充分。空格处应填入副词,词义与long enough接近,词库中sufficiently符合语义。
10.[O] once引导的条件从句里，缺少谓语，因此空格处应该是动词。该从句是对现在的假设，谓语动词应使用一般现在时。the symptoms may return肯定与继续使用电脑有关，resume符合此处语义。注意，不要受空格前的they appeared时态的误导，错误断定此处要使用过去时。