Answer the following questions. 2. Is the length or diameter of a tunnel greater?

1. What is a tunnel?

2. Is the length or diameter of a tunnel greater?

3. When were tunnels discovered?

4. What were tunnels initially used for?

5. Who was the first to notice the potential of tunnels?

6. What was the function of irrigation tunnels?

7. What was the function of tunnels in Middle Ages?

8. What form of transport enabled spreading of tunnels across the world?

9. What are the main reasons for choosing tunnels instead of bridges?

10. What hazards are there with tunnels?

Say if the sentences concerning Text 4A are true or false.

1. A tunnel is an underground or underwater passage that is primarily vertical.

2. Greeks were the first to see the potential of large underground networks of tunnels.

3. Some tunnels are aqueducts to supply water for consumption or hydroelectric stations.

4. Tunnels were initially used for transport of goods and people.

5. Irrigation tunnels were used to transport water though desserts.

6. Due to tunnels Greeks and Romans could transforms marches and create pedestrian tunnels trough very harsh terrains.

7. In Middle Ages tunnels were used only for mining or military.

8. Railroads contributed to spreading of tunnels across the world.

9. Tunnels usually require a larger footprint on each shore than bridges.

10. Reasons for choosing a tunnel instead of a bridge include avoiding difficulties with tides, weather and shipping during construction, aesthetic reasons.

Match the synonyms.