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It is …that (who, which), It is not until…that.
It is these special properties of sound that are the subject of the present chapter.
It was the Dutch physicist Christian Huygens who first offered an explanation for the phenomena.
It was not until about 1911 that a first really successful
theory of atomic structure was suggested by Rutherford.
It was not until Einstein discovered the connection between gravitation and inertia that the mystery Newton could not understand was solved.
Radioactive phenomena occur within the nucleus, and it is here that mass and positive charge resides.
A solenoid carrying a current behaves just like a magnet. It was the great French physicist Ampere who first showed this to be the case.
It is these properties of crystals that are the most important.
It was not until 1953 that this book was published.
It was not until Roentgen discovered X-rays that scientists began to take interest in this subject
Translate the sentences. Pay attention to the meanings of “that” / “those”
Those meters are only used in D. C. circuits.
Resistive transducers fall into 2 groups:
a) those whose resistance is varied by a physical or chemical change, and
b) those whose resistance is varied by the movement of contacts.
3. Then we say that there is an electric current in the conductor.
4. The portion of a wave which lies above the zero current axis is called the positive half cycle and that below the axis is named the negative half cycle.
5. This method is very suitable for small systems like those for the control of high-pressure switch-gear.
6. The action that takes place in the cathode-grid space is analogous to that occurring in a diode tube.
7. The computer also displays information on a system dispatcher’s console in lighted numbers that can be read from a distance.
8. The year of 1897 was that of considerable victory for the inventor of radio, who began experimenting on a large scale.
9. The revived interest in point-contact types of crystal detector during World War II resulted from the fact that these devices can be used at higher frequencies than can vacuum diodes.
10. The flux density at which saturation takes place is less than that for silicon steel.
11. Those most widely used are germanium, silicon, selenium and copper oxide.
12. It is the resistivity that is offered to the flow of current at very high frequency.
13. If the indication is reverse, the indication with normal condition is added to that of the blue wattmeter.
14. This control electrode serves a function analogous to that of the control grid action of an ordinary vacuum tube.
15. The signal voltage that is to be detected is coupled into the tuned grid circuit of the detector.
16. With the same direction of current flow, the heating-cooling effects at the junctions are opposite to those of n-type material.
17. The voltage on the lamp will be greater than that on the other.
18. This field exerts a force on the electron that is in a direction opposite to that of the flux lines.
19. The action is similar to that of a diode, except that the grid still has some rotating effects on the electrons.
IV. Translate the following sentences. Pay attention to the meanings of “one”/”ones”
1. When used for ranges other than this one, the scale readings must be multiplied or divided by a number corresponding to the range.
2. A direct current is one which always flows in the same direction, although it may vary in magnitude.
3. An alternating current is one which varies its direction periodically.
4. This current flows first in one direction and then in the other and the time of each variation is constant.
5. When power is applied one transistor will always conduct a little more heavily than the other.
6. The light-sensitive surface is usually provided with two leads, either one of which may be used.
7. These two constant-voltage outputs are two ones generally used in school and relatively low-powered industrial applications.
8. One should mention that conversion current cannot be set up in solids because the molecules in solids are not free to move from point to point.
9. One should take into consideration that the positive terminal of the meter is connected to the positive terminal of the source.
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