1. British inventor W. Sturgeon exhibited the telephone in 1825.
2. Henrys invention, the telegraph, was not exploited by anyone.
3. Morses early system printed code on tape and it needed an operator to translate it.
IV. .
1. Who used W. Sturgeons device demonstrating its potential for long distances?
a) Alfred Vail did it.
b) Joseph Henry did it.
2. What invention of the 19th century changed the way of communication?
a) the telephone;
b) the telegraph.
V. . .
1. He used pulses to deflect an electromagnet, which moved a marker to produce written codes on a strip of paper.
a) , , .
b) , , .
2. Morses early system produced a paper copy with raised dots and dashes, which were translated later by an operator.
a) , .
b) , .
3. In 1959 Western Union inaugurated Telex, which establishes subscribers to dial each other directly.
a) 1959 Western Union Telex, .
b) 1959 Western Union Telex, .
VI. 4 6 .
4
I. , . .
Example: These samples ( may / have to/ is to) be chosen deliberately. ( ) .
1. The telephone was a vast improvement over the telegraph system, which (could/ may/ is able to) only transmit coded words and numbers.
2. You (has to/ is to/ may) use this instrument for measuring gas pressure.
3. We (couldnt/ cant/ had to) compare the properties of these substances now.
4. We (will be able to/ could/ might) experiment with different metals next week.
II. , , Participle I, Participle II Gerund, , ( ). .
Example: There are several ways of obtaining this substance. (Gerund) .
1. In 1887 Heinrich Hertz, while trying to prove the existence of radio waves, discovered the photoelectric effect.
2. We can start testing the materials as soon as we receive them.
3. Newtons great work published in 1687 is called Principia.
4. The technology of microwave radio is carried one step further by the use of communications satellites.
