Over two thousand years ago Rome(罗马)was the center of a huge empire. The Romans needed a way to move their large armies quickly so that they could protect their huge country. They needed land trade routes, so they joined all parts of their empire by a net-work of roads(公路网).
Beginning in 300 B.C., the Romans built roads in Europe, Asia and North Africa. By 200A.D., they had built 50, 000 miles of almost straight roads.
To build their roads, the Romans moved away all soft soil. They dug until they reached hard ground. Then they added layers(层)of stone and other things. The most important roads were paved(铺设)with large flat(平)stones. Main Roman roads were sometimes as wide as ours today.
To build their roads, the Romans sometimes had to dig tunnels through mountains. But they didn't have any machines to help them. So they heated the rock with fire and then threw cold water over it. When the rock cracked(裂), they dug it out. Roman soldiers and slaves built the roads with their hands and simple tools, but the roads were so well built that they were used for hundreds of years.
1.The story tells us ______ .
A.building roads without modern machines was Roman soldiers'only job
B.it was no easy job for the Romans to build their roads
C.people in advanced countries still use the old Roman way to build their roads today
D.most people in the African countries still use the old Roman way to dig their tunnels through the mountains
2.To build mountain roads, the old Romans had to ______ .
A.explode the rock before they started to dig
B.crack the rock with fire and cold water
C.dig through the hard rock with their hands
D.invent some machines to help them with the work
3.On the whole, the story is about ______ .
A.how to build up our modern roads today
B.Roman tools in building a wide straight road
C.the Romans‘ roads built two thousand years ago
D.the reason why the Romans had to build their roads
4.Why did the Romans build so many roads at that time? It was because ______ .
A.their slaves and soldiers had to do something, or, they would have nothing to do
B.they dared not sail in the ocean and the roads were their only choice
C.they needed land trade roads and the roads to move their grand armies as quickly as possible
D.the old Romans wanted to show how clever they were in building the roads
5.According to the passage, which of the following four choices is correct?
A.The old Romans found soft soil did not make a solid base for the road.
B.The Romans built roads only on flat(平)land
C.Flat stones were mostly used in the roads of Asia
D.The old Romans used to make use of the soft soil for the base of their roads in North Africa