She is widely seen as proof that good looks can lastforever.But,at over 500 years of age, time is catching up with the Mona Lisa.

The health of the famous picture, painted by LeonardoDa Vinci(萊昂納多·達·芬奇)in 1505, is getting worse bythe year, according to the Louvre Museum(盧浮宮博物館)where it is housed."The thin,woodenpanel on which the Mona Lisa is paintedin oil has changed shape since expertschecked it two years ago."the museumsaid.Visitors have noticed the changesbut repairing the world's most famous painting is not easy.Experts are not sure about the materials the Italian artist used and their currentc現在的)chemicalstate.

Nearly 6 million people go to see the Mona Lisa everyyear,and many are attracted by the mystery of her smile."It is very interesting that when you're not looking at her,sheseems to be smiling,and then you look at her and shestops."said Professor Margaret Livingstone of HarvardUniversity."It's because direct visionc視覺)is excellent atpicking up details,but tess suited to look at shadows.DaVinci painted the smile in shadows."

However,the actual history of the Mona Lisa is just asmysterious as the smile.Da Vinci himself loved it so muchthat he always carried it with him,until it was eventuallysold to France's King Francis I in 1519.

In 1911,the painting was stolen from the Louvre by aformer employee,who took it out of the museum hiddenunder his coat.He said he planned to return it to Italy.The painting was sent back to France two years later.

During World Warll,French hid the painting in smalltowns to keep it out of the hands of German forces.

Like many old ladies,the Mona Lisa has someinteresting stories to tell.

1.The underlined sentence in the first paragraph means the Mona Lisa.

A.is losing its value

B.is being damaged after so many years

C.is getting more valuable with years passing

D.will rot away

2.The smile of the Mona Lisa can only be seen_,

A.by indirect vision

B.at a distance

C.by direct vision

D.in shadows

3.Which of the following is TRUE about Mona I.isa?

A.It was once taken away and hidden up by German forces.

B.Its painter himself loved it greatly and always kept it in a shade.

C.Mona Lisa stops smiling when you look at her wantingto see her smiles.

D.King FrancisIbought it and then returned it to Italy.

4.It may add to the difficulty in repairing the painting that~

A.experts haven't noticed changes in its shape asvisitors do

B.it is likely to be stolen again when it's under repair

C.it is uncertain which country,Italy or France,shouldtake charge

D.experts aren't sure about the materials and the chemical state of its oil paint