题目内容：

Chinese archeologists were therefore surprised in the 1990s to find the remains of an ancient fortification (筑城) in Liqian，a remote town in Yongchang county on the edge of a desert area，which was strikingly similar to Roman defense structures.

They were even more astonished to find West­ern­looking people with green，deep­set eyes，long hooked noses and blond hair.

Though the villagers said they had  never traveled outside the county，they worshipped bulls and their favorite game was similar to the ancient Romans' bull­fighting dance.

DNA tests in 2005 confirmed some of the villagers were indeed of Caucasian origin，leading many experts to conclude they are descendants of an ancient Roman army headed by general Marcus Crassus.

“The‘foreign’origin of the Yongchang villagers，as proven by the DNA tests，does not necessarily mean they are of ancient Roman origin.”

Xie Xiaodong，a geneticist from Lanzhou University，also sounded a skeptical note.

“Even if they are descendants of Romans，it doesn't mean they are necessarily from that Roman army，” Xie said.

Their mysterious identity has brought wealth and fame to some of the villagers.

Cai Junnian has yellow wavy hair，a hooked nose and green eyes.A DNA test in 2005 confirmed he is of 56 percent European origin.It made him famous almost overnight.

Reporters，filmmakers，historians and geneticists from around the world pursued him.A Beijing film producer will spend millions to turn the villagers' story into a film.

Lanzhou University's new research body，set up this week by Chinese and Italian anthropologists，is a platform for experts to further research the subject but the research work will certainly be complicated.

The center will help Chinese learn Italian language and culture，he said.“More exchanges will certainly be helpful in unraveling the mystery.”

1.Scientists take DNA tests in order to ________.

A. explain why villagers have the Western­looking

B. explain why ancient Roman army disappeared

C. explain why villagers are infected with AIDS

D. explain why villagers married at an early age

2.Which is NOT true according to the passage?

A. Romans like bull­fighting dance.

B. The villagers are of ancient Roman origin.

C. The research work will be very complicated.

D. Cai Junnian's European origin makes him famous overnight.

3.What's the meaning of the underlined word“unraveling” in the last paragraph?

A. Keeping.    B. Discovering.

C. Storing.    D. Destroying.

4.Which of the following would be the BEST title for the passage?

A. Chinese Villagers Descended from Roman Soldiers

B. Unforgettable and Fierce Ancient Roman War

C. Similarities Between Chinese and Western People

D. An Introduction to Roman Defense Structures