The National Gallery of Art in Washington, D.C., is one of the world's greatest

The National Gallery of Art in Washington, D.C., isone of the world's greatest art museums. Millions of people have entered itsdoors to see paintings by the world's fine artists. But if these pricelessmasterpieces are to be preserved, the Gallery must protect them carefully. TheGallery's 135-man guard force has successfully prevented them from beingstolen, but protecting the paintings from nature is a greater problem.

In past times, the owners of paintings did not protectthem from damaging changes in humidity (湿度) andtemperature. As a result, the life of these paintings were shortened. In theNational Gallery, however, humidity and temperature are carefully controlled.The building is air-conditioned in summer and heated in winter. Theair-conditioning and heating system are so important to the life of thepainting that the Gallery has two of each system. If one should fail, the extraone 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 darkchurches and palaces. A coat of varnish (清漆) was aprotection from the weak light. But when museums took over the care of manypaintings, they were often hung in brighter light than before. Soon they werein danger of fading. The damaging effects of light were increased when themuseums removed the varnish coating, yellowed with age.

To protect its paintings, the National Gallery put aspecial kind of glass in its skylights. This glass allows visible lights toenter the building but it keeps out harmful ultraviolet rays. The Gallery hasalso developed new and better varnishes which help to keep paintings fromfading. Thanks to these new precautions, many of the world's greatestpaintings are being well protected for future generations to enjoy.

1.The text mainly tells us about ______.

A．the guardforce in the National Gallery

B．protectinggreat paintings from nature

C．pricelesspaintings of past times

D．theair-conditioning and heating systems in the National Gallery

2.The underlined word "precautions" inParagraph 4 is closest in meaning to ______.  

A．decorations

B．problems

C．suggestions

D．applications

3.From the text we can infer that_______.

A．great artistspainted in dark churches and palaces

B．you can touchthese paintings while you are in the National Gallery

C．the care ofthe world's greatest paintings is both a big responsibility and a greatchallenge

D．the guardforce in the Gallery has not done a good job

试题答案

【答案】

1.B

2.D

3.C 

【解析】

试题