B. 2. Translate the sentences paying attention to the underlined words

Date: 2015-10-07; view: 673.

1. It is doubtful whether the construction of the pyramids of Egypt could be made without the existence of roads. 2. In making tunnels it is most necessary to know the character of the rock, especially whether hard or soft. 3. The professor asked the student whether he knew the properties of several building materials. 4. We determine whether the material is good for building purposes judging by its qualities. 5. A greater speed in housing construction will be achieved, provided building materials are changed into units of assembly. 6. A water supply system has providedthe city of ancient Rome with water in the year 512 before our era.

B. 3. Translate the sentences paying attention to SINCE

1. I cannot join the event since I will attend a training course tomorrow night. 2. We still use alcohol in modern thermometers, since its expansion is greater than the expansion of mercury. 3. The phenomena of nature are of great importance since weather is one of the chief elements in man's life. 4. Since ancient times people studied nature and natural phenomena. 5. Since there is so much water, some people think that it is of little value or interest.

C. 1. Read the text Earthquakes and answer the questions:

1. What is an earthquake?

2. Where does the greatest danger of an earthquake come from?

An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. An earthquake is the result of great pressures brought about as slabs of the earth's crust rub against each other. These pressures are exerted as the earth moves ever so slightly. When these pressures become greater than the rock layers can endure, a snapping and shifting movement results. Throughout human history, hundreds of thousands of people have lost their lives due to earthquakes. The movement of the ground during a quake is mea­sured by a seismograph.

In 1935, American seismologist Charles Richter developed a scale that measures the magnitude of seismic waves. Called the Richter scale, it rates earth tremors on a scale from 1 to 9, with 9 being the most powerful and each number representing an increase of ten times the energy over the previous number. According to this scale, any quake that is higher than 4.5 can cause damage to stone buildings; quakes rated a magnitude of 7 and above are considered very severe. They have potential for causing much injury, death, and property damage.

Most earthquakes are not even noticed by the general public, since they happen either under the ocean or in unpopulated areas. Some earthquakes are too small to be felt but can cause movement of the earth, opening up holes and displacing rocks. Shock waves from a very powerful earthquake can trigger smaller quakes hundreds of miles away from the epicenter. Moderate earthquakes (5.0-5.9) happen more than twice daily. Approximately 1,000 earthquakes measuring 5.0 and above occur yearly. Major earthquakes (7.0-7.9) occur about 18 times a year. Sometimes an earthquake under the ocean can be so severe, it will cause a tsunami, responsible for far greater damage.

The greatest danger of an earthquake comes from falling buildings and structures and flying glass, stones and other objects. Another concern is the matter of fallen elec­trical wires, broken gas lines and water pipes. The gas leaking from broken lines can ignite and explode, causing extensive damage and triggering destructive fires. Following an earthquake, water should be shut off if lines have been damaged or broken; the same applies to the main gas valve. Windows in a structure should be opened if there is any possibility of a gas line leak.

Scientific research has improved the predictability of possible earthquakes. Several systems are used to predict the onset of an earth­quake, such as counting the microquakes and recording their buildup over a period of time. By means of laser beam, light-wave movement in the earth's crust of as little as twenty trillionths of an inch can be recorded.

In spite of extensive research and sophisticated equipment, it is impossible to predict an earthquake, although experts can estimate the likelihood of an earthquake occurring in a particular region.

Alarm systems have been developed in parts of the country where earthquakes are most likely to occur to notify people that conditions are present for such an emergency. These early earthquake warning procedures are useful. Yet, in order for them to be most effective, they must be accurate. False announcements will lead people to ignore le­gitimate attempts at early earthquake warning.

It is doubtful if measures can be developed to protect everyone from the destruction accompanying major quakes. However, it is im­portant to know and practice effective measures for the protection of citizens. Homes and office buildings can be designed and con­structed to prevent building collapse during an earthquake. For example, steel reinforced concrete slabs under buildings provide a foundation that can absorb the shocks of an earthquake. The use of anchor bolts helps to secure the building to this foundation. Buildings constructed of structural steel and reinforced concrete tend to withstand earthquakes quite well. The value of constructing buildings with earth­quake protection in mind was demonstrated in the 1989 San Francisco quake when the majority of modern structures in that area were not seriously damaged.

D. 1. Comment on the following:

1. Most earthquakes are not even noticed by the general public.

2. It is doubtful if measures can be developed to protect everyone from the destruction accompanying major quakes.

3. Scientific research has improved the predictability of possible earthquakes.