Ғ. Н.Қисметова Ағылшын тілі грамматикасы
carry heavy loads at high speeds for long distances. What was more, the
жүктеу/скачать 3.76 Mb. Pdf көрінісі
|
| carry heavy loads at high speeds for long distances. What was more, the
ending of the war meant that thousands of aeroplaneb and skilled pilots were available. The first aeroplaneb were machines that had been used as bombers. They were quickly converted for use by passengers by fitting extra seats and windows. The first regular public air service from London to Paris was started in August 1919. 4. During World War П the value of aeroplanes for carrying heavy oads was recognized. This led after the war to an increase in the practice ^ sen d in g goods by air. Air freight is expensive but it often thought worth while for such goods as early vegetables, fruits and flowers, as well as for t ngs urgently needed such as spare parts for machinery, medical supplies, films and photographs. Some parts of the world being hundreds of miles rom a road, railway or waterway, air transport is the only possible kind. 140 Such places are kept supplied wholly by air.. 5. After World War П, bigger and faster airliners were introduced. Jet-propelled aircraft were first used in 1950. Air transport is very valuable for emergency medical work. The most important use of air transport besides carrying passengers is carrying mail. If the letters are sent by air mail, they are not long in coming. Although it is unlikely that aircraft will ever replace ships for carrying heavy and bulky cargoes such as oil, coal, minerals, grain and machinery, air transport is already proving a serious rival to passenger ships on some routes. 6. Helicopters are Hovercraft. 1 Helicopters are very useful in places where there is no room for long, flat runways. Madem turbo-jet airliners need a run of nearly two m iles lang to take off, but helicopters can use small fields, platfarms mounted on ships and the flat tops of buildings. Helicopters were first introduced for regular airline service 1947. Later, helicopters were used for canying passengers and mail on short routes, and for taking airline passengers between the centres of cities and the main airports. 7. While helicopters gain in needing very little space for taking-off and landing, they lose because the speed at which they move forward is quite low. So the problem was to develop an aircraft combining the advantages of the helicopter with the high speed of an ordinary aircraft. If the designers could develop such a machine the problem would besalved. So far this purpose the hovercraft was designed. Hov ercrafts are likely to be useful for ferry services - for exam ple, in ferrying motor cars across the English Channel. They may also be useful for travel in roadless countries. жүктеу/скачать 3.76 Mb. Достарыңызбен бөлісу:
|