Comprehension check. I. Decide whether the following statements are true or false according to the text:

I. Decide whether the following statements are true or false according to the text:

1. Viaducts like bridges cross water.

2. Viaducts cross water and dry land instead of merely extending from one bank to the other.

3. Viaducts carry railroad tracks over valleys.

4. Viaducts are built on the same level on the land to carry railroads.

5. Greeks built the first viaducts.

6. Parts of the longest viaducts were destroyed by a(n) earthquake in 1925.

7. The spans of the viaduct over the River Tay are over 2 miles long.

8. Many agricultural societies have constructed aqueducts to supply large cities with water.

9. The famous Roman aqueducts were ruined long ago.

10. In California large aqueducts supply water to New-York.

II. Complete the sentences with the best answer:

1. Some viaducts can cross

a) water b) dry land c) cross water and dry land.

2. Most viaducts consist of a series of supports under

a) beam construction b) arch construction c) beam-and slab or arch construction.

3. Some viaducts are built higher than the level of the land to carry

a) bridges b) roads c) railroads or to make a safe crossing over railroads

4. The Tunkhannock viaduct is

a) 2,375 feet long b) 1,947 feet long c) 2,357 feet long.

5. Archimedes invented the water screw

a) to irrigate crops b) to supply large cities with drinking water

c) for transportation purposes

6. In California two aqueducts are from

a) the Colorado River b) the Oven River c) Mississipi River

7. In the past aqueducts often had channels made of

a) concrete b) polymers c) dirt.

8. In some cases a new aqueduct is built

a) alongside the old one b) over the old one c) under the old one.

III. Answer the questions:

1. What do viaducts cross?

2. What do they carry?

3. Why are some viaducts built higher than the general level of the land?

4. What did the ancient Romans build the first viaducts for?

5. What are the longest viaducts?

6. What is the use of aqueducts?

7. What were channels made of in the past?

8. Why is in some cases a new aqueduct built alongside the old one?

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