The National Gallery of Art in Washington, D.C., is one of the world's greatest art museums. Millions of people have entered its doors to see paintings by the world's fine artists. But if these priceless masterpieces are to be preserved, the Gallery must protect them carefully. The Gallery's 135-man guard force has successfully prevented them from being stolen, but protecting the paintings from nature is a greater problem.
In past times, the owners of paintings did not protect them from damaging changes in humidity (湿度) and temperature. As a result, the life of these paintings were shortened. In the National Gallery, however, humidity and temperature are carefully controlled. The building is air-conditioned in summer and heated in winter. The air-conditioning and heating system are so important to the life of the painting that the Gallery has two of each system. If one should fail, the extra one can take over.
Light is another enemy of paintings. Ultraviolet rays (紫外线) in light cause paintings to fade (褪色). Long ago, paintings often hung in dark churches and palaces. A coat of varnish (清漆) was a protection from the weak light. But when museums took over the care of many paintings, they were often hung in brighter light than before. Soon they were in danger of fading. The damaging effects of light were increased when the museums removed the varnish coating, yellowed with age.
To protect its paintings, the National Gallery put a special kind of glass in its skylights. This glass allows visible lights to enter the building but it keeps out harmful ultraviolet rays. The Gallery has also developed new and better varnishes which help to keep paintings from fading. Thanks to these new precautions, many of the world's greatest paintings are being well protected for future generations to enjoy.
小题1:The text mainly tells us about ______.
A．the guard force in the National Gallery
B．protecting great paintings from nature
C．priceless paintings of past times
D．the air-conditioning and heating systems in the National Gallery小题2:The underlined word "precautions" in Paragraph 4 is closest in meaning to ______.
A．decorations
B．problems
C．suggestions
D．applications小题3:From the text we can infer that_______.
A．great artists painted in dark churches and palaces
B．you can touch these paintings while you are in the National Gallery
C．the care of the world's greatest paintings is both a big responsibility and a great challenge
D．the guard force in the Gallery has not done a good job
小题1:B
小题2:D
小题3:C
题目分析：这篇文章讲的是如何保护名画不受自然的侵害。博物馆采用了一些新的方法保护这些名画。
小题1:从第一段的句子：but protecting the paintings from nature is a greater problem.可知这篇文章讲的是如何保护名画不受自然的侵害。选B。
小题2:猜词题：前面讲的是应用一些新的方法保护这些名画。选D
小题3:推理题;从第三段的句子：But when museums took over the care of many paintings, they were often hung in brighter light than before. Soon they were in danger of fading. The damaging effects of light were increased when the museums removed the varnish coating, yellowed with age.可知这些名画的保护既是责任也是挑战。选C
点评：本文要求考生读懂文章中的每个句子的意思还要推理它们之间的关系，理解文章的言外之意，从而揭示文章的深层涵义。任何一篇文章都有其特定的写作目的，读者应当知道如何去做或按照某种方式传递思考问题。推理判断题的答案不可能在文章中直接找到，因此推理时我们务必要忠于原文，在文章中寻找并确定可推论的依据。
