题目内容：

A camera and a computer can “see” something that perhaps millions of pairs of eyes failed to see for 480 years: the Mona Lisa’s necklace. The discovery about the famous painting was made by an American physicist.

The Mona Lisa, painted by the Italian, Leonardo da Vinci, has been on show for many years in Paris. Now a row of white spots on the neck have been “seen”. They are said to be the remains (痕迹) of a necklace which the artist later painted over.

The painting will be examined further by using infrared scanning (红外线扫描) techniques. Laser (激光) technology can be used to show what lies directly under the surface of the finished work, too. This will help us to understand how the artist drew the picture: Did he begin with a quick-made drawing or have second thoughts as he painted the picture?

This kind of knowledge will show us the famous artist at work. It may also help to explain Mona Lisa’s smile, which has puzzled art lovers for centuries.

1.This passage is mainly about ______.

   A. the famous artist Leonardo da Vinci

B. an American physicist’s discovery

   C. further researches on the Mona Lisa

D. The uses of modern technology

2.The Mona Lisa is ______.

   A. a famous artist                  B. a famous painting

C. a smiling woman    D. a lost necklace

3.In this passage, “the Mona Lisa’s lost necklace” suggests that ______.

   A. Mona Lisa once wore a necklace

   B. someone stole the necklace from the Mona Lisa

   C. the artist did not keep the necklace he had painted on the neck

   D. the artist had a necklace stolen while working on the painting

4.According to the passage, the white spots on Mona Lisa’s neck ______.

   A. are still invisible to visitors

B. have turned into a necklace

   C. have already appeared before visitors

D. are looking more and more like a necklace

5.The painting will be examined further so that people may know more about ______.

   A. Mona Lisa and her smile

B. the time when it was finished

   C. infrared scanning and laser

D. this art work and the artist