题目内容：

    The Silk Road is arguably the most famous long-distance trade route of the ancient world. This passage connected Europe in the West with China in the East, and allowed the exchange of goods, technology, and ideas between the two civilizations. Although merchants could make huge profits travelling the road, it was not without risk.

The main Silk Road started in Chang’an (known today as Xi’an), the early Han capital. Travelers commencing their journey from this city could take a northern route that would take them across China’s northwestern provinces. After this, they would face the Gobi Desert, arguably the greatest danger of the Silk Road.

The Gobi Desert, the largest desert in Asia, consists mainly of rocky, hard earth. This feature made it easier for traders to travel across, compared to sandy deserts like the neighboring Taklamakan Desert. Like other deserts, the Gobi Desert is dry and hot, and therefore the biggest challenge travelers faced was obtaining enough water for themselves as well as for their camels.

So, rest stops were created along the route, allowing travelers to rest,  eat and drink. These  places also promoted the exchange of goods, and even ideas, amongst the travelers who stopped there. Usually, the rest stops were placed within a day’s journey of each other. In this way, travelers could avoid spending too much time in the desert, which would make them targets for robbers, another danger of the Silk Road.

Once through the Gobi Desert, travelers would continue their journey into Iran, Turkey, and finally Europe. Whilst this part of the journey may have been less dangerous, it is not entirely  without its perils.

1.The underlined word “it” in the first paragraph refers to _____.

A.making huge profits B.traveling the Silk Road

C.exchanging goods and ideas D.connecting different civilizations

2.Why was the Gobi Desert easier to cross than other deserts?

A.The desert’s surface was easier to walk on.

B.Camels for transportation were easier to find.

C.It was smaller and could be crossed in less time.

D.There were more natural water sources available.

3.What can we guess about the rest stops in the Gobi Desert?

A.Travelers were offered free accommodation.

B.They were located around the edges of the desert.

C.Travelers staying there were often attacked by criminals.

D.They were shared by travelers from different countries.

4.What is the passage mainly about?

A.The origins of the Silk Road.

B.The benefits of the Silk Road.

C.The difficulties faced by Silk Road travelers.

D.The cultural exchanges among Silk Road travelers.