pollute the atmosphere with exhaust gases. As to the magnetically-suspended vehicles, they are silent in operation and do not produce air pollution, which makes them attractive for big cities and suburban areas.
1.What factors determine the safety on railways?( 1. Safety depends on many factors. First of all, it is determined by the condition of the track. Track-testing cars1 driven slowly along the lines show the engineer where the track must be repaired and a great deal of track main*"" tenancy machines are available to keep the track well maintained.)
2. What types of railway equipment help the railwaymen keep the track in a good operating condition?( 2.In discussing railway safety consideration should also be given to efficient braking systems. From the very beginning, railway men attached great importance to the problem of stopping trains. At first, the brakes were installed in the locomotives, then they were fitted on passenger vehicles.) 3. Who devised the method of stopping trains by compressed air? (3. The most significant achievement in braking trains was undoubtedly made in 1872 when George Westinghouse, an American, suggested that automatic air brakes should be installed in the trains.)4. Why did the early brakes give way to the Westinghouse brakes? (While undergoing a test the train equipped with the Westinghouse brakes approached a tunnel. Suddenly the driver saw a horse and a wagon on the track directly ahead. Immediately he applied the air brake. There came a scream of metal on metal and the train stopped. It seemed like a miracle! Never before in all the railway history had a train been stopped so fast.) 5. What made railways invent different methods of signalling?( The need for signalling arose when the number of trains increased and it was necessary that the train movements should be directed by one way or another. The function of the early signals was to ensure a certain interval of time between trains lest trains should collide. However, the time interval method, as it was then called, soon became unsatisfactory because with the increased number of trains and cases of their late arrival at stations this method could not ensure the interval of space) 6. What were the main steps in the evolution of signalling and what was the purpose of each method used?( 6. The modification of this method is the modern block system under which the line is divided into short sections or blocks and a fixed colour-light signal is placed at the entrance to each block. The function of the block signal is not to admit a train to a block section if the latter is occupied by another train.) 7. What is CTC and how are train movements governed under CTC? (8. Weather conditions can also prevent the driver from reading the wayside signals. Sometimes the drivers themselves are not careful enough. This has made the railways change radically the entire system of signalling.) 8. What may cause accidents on high-speed and superhigh-speed railways?( Weather conditions can also prevent the driver from reading the wayside signals. Sometimes the drivers themselves are not careful enough. This has made the railways change radically the entire system of signalling.) 9. How is the problem of safe train operation solved nowadays? (The key to solve the problem of train operation has been found in the so-called semi-automatic driving of trains which is indispensable for safe operation of trains moving at top speed) 10. What is meant by semi-automatic driving of trains?( By semi-automatic driving of trains is meant the use of locomotive cab signals and automatic train stop devices. ) 11. How do cab signals and automatic train stop devices help the drivers avoid accidents? (From what has been said above it follows that careful track maintenance, efficient brakes and reliable signalling are the factors which assure safe running of trains at high and super-high speeds thereby increasing the track carrying capacity and improving the utilization of the rolling stock.)
III Write the annotation to the text given above.
IV Match the sentences
You could have done much better in the exam … f
If the weather had been nice ….............................e
I wouldn’t have bought that book …....................c
She would have gone to Japan last summer ….....a
If I hadn’t taken an umbrella ….............................d
That building wouldn’t have fallen down …..........b
… if she had spoken Japanese quite well.
… if it hadn’t been so old.
… if I’d known how dull it was.
… I would have got wet.
… we could have gone horse-riding.
… if you had taken private lessons.
V Rewrite the following sentences using the passive voice.
My grandfather built this house in 1917. This house was built in 1917 by my grandfather
By this time tomorrow, we will have closed the contract. The contract will have closed by this time tomorrov.
Shakespeare wrote Romeo and Juliet. Romeo and Juliet was written Shakespeare
