She is widely seen as proof that good looks can last for ever．But, at nearly 500 years of age, time is catching up with the Mona Lisa．
The health of the famous picture, painted by Leonardo Da Vinci in 1505, is getting worse by the year, according to the Louvre Museum(卢浮宫博物馆)where it is housed．
“The thin, wooden panel on which the Mona Lisa is painted in oil has changed shape since experts checked it two years ago, ” the museum said．Visitors have noticed changes but repairing the world’s most famous painting is not easy．Experts are not sure about the materials the Italian artist used and their current chemical state(化学状态)．
Nearly 6 million people go to see the Mona Lisa every year, many attracted by the mystery of her smile．“It is very interesting that when you’re not looking at her, she seems to be smiling, and then you look at her and she stops, ” said Professor Margaret Livingstone of Harvard University．“It’s because direct vision(视觉)is excellent at picking up detail, but less suited to looking at shadows．Da Vinci painted the smile in shadows．”
However, the actual history of the Mona Lisa is just as mysterious as the smile．Da Vinci himself loved it so much that he always carried it with him, until it was eventually sold to France’s King Francis I in 1519．
In 1911, the painting was stolen from the Louvre by a former employee, who took it out of the museum hidden under his coat．He said he planned to return it to Italy．The painting was sent back to France two years later．
During World War II, French hid the painting in small towns to keep it out of the hands of German forces．
Like many old ladies, the Mona Lisa has some interesting stories to tell．
(1)
What does the writer mean by “time is catching up with the Mona Lisa”?
[ ]
A．
The painting woman is not so beautiful any more．
B．
Ageing is something that affects us all．
C．
The painting needs repairing．
D．
At such an old age, she is no longer popular．
(2)
What makes the repair work difficult?
[ ]
A．
The wooden panel is thin and old．
B．
No one knows exactly what materials were used to create the painting and how it might respond to treatment．
C．
The health of the painting is suffering．
D．
Experts can’t agree on how to carry out repairs．
(3)
What makes her so mysterious according to Professor Livingston?
In the atmosphere, carbon dioxide acts rather like a one-way mirror or the glass in the roof of a greenhouse which allows the sun's rays to enter but prevents the heat from escaping．
According to a weather expert' s prediction, the atmosphere will be 3℃warmer in the year 2050 than it is today, if man continues to burn fuels at the present rate．If this warming up took place, the ice caps in the poles would begin to melt, thus raising sea level several metres and severely flooding coastal cities．Also, the increase in atmospheric temperature would lead to great changes in the climate of the northern hemisphere(北半球), possibly resulting in an alteration of the earth's chief food growing zones．
In the past, concern about a man-made warming of the earth has concentrated on the Arctic because the Antarctic is much colder and has a much thicker ice sheet．But the weather experts are now paying more attention to West Antarctic, which may be affected by only a few degrees of warming, in other words, by a warming on the scale that will possibly take place in the next fifty years from the burning of fuels．
Satellite pictures show that large areas of Antarctic ice are already disappearing．The evidence available suggests that a warming has taken place．This fits the theory that carbon dioxide warms the earth．
However, most of the fuel is burnt in the northern hemisphere, where temperatures seem to be falling．Scientists conclude , therefore, that up to now natural influences on the weather have gone beyond those caused by man．The question is：Which natural cause has most effect on the weather?
One possibility is the variable behavior of the sun．Astronomers at one research station have studied the hot spots and "cold" spots(that is, the relatively less hot spots)on the sun．As the sun rotates(使旋转), every 27.5 days, it presents hotter or "colder" faces to the earth, and different aspects to different parts of the earth．This seems to have a considerable effect on the distribution of the earth's atmospheric pressure, and consequently on wind circulation．The sun is also changeable over a long term：its heat output goes up and down in cycles, the latest trend being downward．
Scientists are now finding shared relations between models of solar weather interactions and the actual climate over many thousands of years, including the last Ice Age．The problem is that the models are predicting that the world should be entering a new Ice Age and it is not．One way of solving this theoretical difficulty is to assume a delay of thousands of years while the solar effects overcome the inertia(惯性)of the earth's climate．If this is right, the warming effect of carbon dioxide might thus be serving as a useful opposed balance to the sun's fading heat．
(1)
It can be concluded that a concentration of carbon dioxide in the atmosphere would ________．
[ ]
A．
mean a warming-up in the Antarctic
B．
raise the temperature of the earth' s surface
C．
prevent the sun's rays from reaching the earth's surface
D．
explain the cause of great changes in the climate in the northern hemisphere
(2)
The article was written to explain ________．
[ ]
A．
the greenhouse effect
B．
the solar effects on the earth
C．
the causes affecting weather
D．
the models of solar-weather interactions
(3)
Although the fuel consumption is greater in the northern hemisphere, temperatures there seem to be falling．This is ________．
[ ]
A．
mainly because the levels of carbon dioxide are rising
B．
partly due to changes in the output of solar energy
C．
possibly because the ice caps in the poles are melting
D．
only due to the effect of the inertia of the earth' s climate
(4)
On the basis of their models, scientists believe the opinion that ________．
[ ]
A．
the climate of the world should be becoming cooler
B．
the new Ice Age will be delayed by the greenhouse effect
C．
the man-made warming effect helps to increase the solar effects
D．
it will take thousands of years for the inertia of the earth's climate to take effect
(5)
If the assumption about the delay of a new Ice age is correct, ________．
[ ]
A．
ice would soon cover the northern hemisphere
B．
the greenhouse effect could work in favor of the earth
C．
the best way to overcome the cooling effect would be to burn more fuels
D．
the increased levels of carbon dioxide in the atmosphere could warm up the earth even more quickly
