1.The waster radiation is revolutionizing X-ray science，enabling researchers to
see things on an atomic level with eyes that are a million times more powerful than ever before.
2.If we had known the properties of the material, we should have made full use
3.Moving parts of a machine would wear much more rapidly without being
4.Cool slowly to minimize cracking.
5.Don’t let the stresses inside the material exceed the elastic limit, or else
permanent deformation will result.
6.Attention must be paid to the working temperature of the machine.
7.Television is the transmission and reception of image of moving objects by
8.An understanding of the essential character of scientific investigation is best
acquired from the study of a representative particular science.
要了解科学研究最本质的特点，最好是对特定的典型学科进行研究。9.Apart from the international agencies controlled by the U.N., many scientific
and technological organizations, both governmental and privately owned, are pooling their resources and incorporating themselves into supra-national bodies; a good example is the Organization for Economic Cooperation and Development, with over 20 member-countries throughout the world.
https://www.sodocs.net/doc/604738016.html,puting machines are essentially machines for recording numbers,
operating with numbers, and giving the result in numerical form.
计算机的本质上是一种记录数字、运算数字并给出数字结果的机器。11.There now exists a kind of glass so sensitive to light that, like photographic
film, it will record pictures and designs.
现在有一种对光十分敏感的玻璃，它像胶卷一样能记录图像和图案。12.The ON condition makes the data equipment ready to the communication
equipment to be connected to the communication channel.
13.Then the surgeon cut him open and take out the appendix and stitched him up
14.It is very much like communicating with an accurate robot who has a very
small vocabulary and takes everything literally.
15.Design is a series of operations involved in taking a product from a
conceptual stage to a form that meets both company goals and customer expectations.
16.Jigang will fix this problem during the recent shut down of the finishing mill.
17.Many health-conscious women increase their risk by rejecting red meat,
which contains the most easily absorbed form of iron.
18.As we know, all matters consist of molecules, and molecules consist of atoms.
19.Dimensioning is a complicated word and long experiences are required for the
mastering of it.
20.This laser beam covers a very narrow range of frequencies.
21.The diameter and the length of the wire are not the only factors to influence
22.The shadow cast by an object is long or short according as the sun is high up
in the heaven or near the horizon.
23.Quasi-stars were discovered in 1963 as a result of an effort to overcome the
shortcomings of radio telescopes.
24.Earthquakes seem less easy to be controlled by man than weather.
25.These waves, which are commonly called radio waves, travel with the
velocity of light.
1.Gases differ from solids in that the former have greater compressibility than
2.The application of electronic computers makes for a tremendous rise in labor
3.The flowing of current first in one direction, and then in another makes an
4.If we were ignorant of the structure of the atom, it would be impossible for us
to study nuclear physics.
5.Both of the substances are not soluble in water.
6.Whenever one body touches another, heat always passes by conduction from
the warmer to the colder.
7.All of this proves that we must have a profound study of properties of
8.The wide application of electronic computers affects tremendously the
development of science and technology.
9.Gasoline is appreciably volatile.
10.These parts must be proportionally correct.
11.In this case the temperature in the furnace is up.
12.Without steel, there would be no modern industry.
13.The new precision machine tools are very good in quality and fine in shape.
14.Matter can be changed into energy, and energy into matter.
15.The bond between mathematics and the life sciences has been strengthened by
the emergence of a whole group of applied mathematics specialties, such as biometrics, psychometrics, and economics.
16.The frequency, wave length, and speed of sound are closely related.
17.The temperature needed for this processing is lower than that needed to melt
18.Oxidation will make metals rusty.
19.Being large or small all magnets behave the same.
20.For reasons the alternating current is more widely used than the direct current.
21.A new kind of computer-small, cheap, fine-is attracting increasing attention.
22.In general, all the metals are good conductors, with silver the best and copper
23.A computer system consists of a computer and some peripherals.
24.The resistance of a given section of an electric circuits is equal to the ratio of
its voltage to the current through this section of the circuit,
25.Given the weight and the specific gravity of a body, we can calculate its
26.Since copper possesses good conductivity, it is widely used in electrical
27.The diameter and the length of wire are not the only factors to influence its
28.Its transmission over long distance causes some loss of energy.
29.Turning this knob gives the control over the brightness of the light spot.
30.Pure water freezes at 0℃and boils at 100℃under standard pressure.
在标准大气压下，纯净水在摄氏零度时结冰，在摄氏一百度时沸腾。31.Ductility of a metal is usually much less when hot than when cold.
32.Stainless steel posseses good hardness and high strength.
33.The time-keeping decives of electric watches are much more accurate than
those of mechanical ones.
34.Oceans do not so much divide the world as unite it.
35.X-rays have the same nature as visible light, but their wavelength is much
36.It takes a body precisely as long to fall from a height h as it does to rise that
37.There are two kinds of video capture devices, analog and digital.
38.Increasingly sophisticated computer-controlled robots are entering industry to
cut down production costs, time and labor requirements.
39.Even the dissolution in water cannot enable common salt to change its
40.They worked out a new method by which production has been rapidly
41.The water must be kept free from harmful bacteria. It should be colorless and
42.Fig.1 incorporates many of the factors which must be considered in
developing a satisfactory system.
43.Other metals are not malleable at all. Thus chromium is so hard even at room
temperature that it shatters whenever it is hammered.
44.Water is a substance suitable for preparation of hydrogen and oxygen.
45.Faraday discovered the Law of Electromagnetic Induction after years of trial,
error, and trial again.
1.When an acid reacts with a base, a neutral product usually results, and we call
it a salt.
2.The key difference between Japanese and German maglev trains is that the
Japanese trains use super-cooled, superconducting electromagnets.
3.Insulators can also conduct electricity to some extent, though they give a high
resistance to an electric current.
4.The two units used most frequently in electricity are ampere and volt; This is
the unit of voltage and that of current flow.
5.The closed loop system protects the operator from liquor contact and hazard
6.Ideal voltage and current sources are active circuit elements, while resistors
and conductors are passive elements.
理想电压源和电流源都是有源元件，而电阻器和导体都是无源元件。7.The liquid carries the current through cell between the two plates.
8.The interference worked much instability in the system.
9.Whichever way the two two-way switches are left, one of the wires is “alive”
and the other is “dead”.
10.The thicker the wire, the more freely it will carry current.
11.Gold is similar in color to brass.
12.In general, all the metals are good conductors, with silver the best and copper
13.Adverse to iron, mercury is in a liquid state at ordinary temperature.
14.The change of electrical energy into mechanical energy is done in motors.
15.The computer can read in and out information in less than a second.
16.With its great potential, the wide use of optical communications will not come
17.If one halves a bar magnet, each of the two halves will be a complete magnet.
18.It is through this interface that the substation operator must control and
monitor the entire substation.
19.The same is true when an alternating voltage is applied to a resistance.
20.If we permit the current to flow longer, more heat will be produced.
21.Small as they are, atoms are made up of still smaller units known as”
22.The choice of material in construction of bridges is basically between steel or
concrete and main trouble with concrete is that its tensile strength is very small.
23.The distance between the two plates is small compared with their linear
24.The cost of gold is high. That is why it is not extensively used as conductors.
25.Practically all substances expand when heated and contract when cooled.
26.The materials are excellent for use where the value of the work pieces is not
27.The new chip is about 1.5 times as integrative as that of the old ones.
28.The electricity crisis can be solved as long as low-cost power is available.
29.The dielectric material is not perfect, so a small leakage current will flow
30.The electrons to move freely play an important role in the formation of
31.The moving point P describes a line, straight or curved, in the plane.
32.Such recent terms as chemical physics and biophysics are indicative of the
widening application of the principles of physics, even in the studies of living organisms.
33.This complicated relationship must be represented graphically.
34.The reserve voltage gain can usually be neglected.
35.The expansion of metal on heating must be taken into consideration before a
long metal bridge is built.
36.AC can be changed into DC with great ease.
37.Going through the process of heat treatment, metals become much stronger
and more durable.
38.Modern industry needs considerable quantities of this metal, either in the
form of iron or in the form of steel.
现代工业对这种金属的需求量很大，无论是铁的形式还是钢的形式。39.The composites showed a two times increase in modulus of elasticity and a
five times increase in tensile strength over that of the plain matrix.
40.If you treble the distance between an object and the earth, the gravitational
attraction gets nine times weaker.
1.Being cooled in the air, this kind of steel becomes harder and harder.
https://www.sodocs.net/doc/604738016.html,ing a transformer, power at low voltage can be transformed into power at high
3.Copper has less resistance than aluminum for the same size wire, but aluminum,
being much lighter in weight, has less resistance per unit of weight.
4.Depending upon certain conditions, there may or may not be free electrons in
5.In fact, materials as used in transistors do not exist in nature but are man-made.
6.The porous wall acts as a kind of seine for separating molecules.
7.It is necessary to prevent induction motors against overload and under voltage.
8.Transistors, integrated circuits, and the chip itself only came about because
materials scientists learned how to process silicon from common beach sand.
9.The function of the safety value is to reduce accident.
10.Another important factor to be taken into consideration is that current strength is
equal at certain points in a series circuit.
11.To run a direct current motor, we must connect it to a direct current source.
12.It was not until the 19th century, when magnetism was shown to be the product of
electricity, that serious research into the nature of permanent magnetism began.
13.A minimum electric power system is shown in Fig.1, a combination of an energy
source, a prime mover, a generator, and a load.
最小的电力系统如图1所示，它由能源，原动机，发电机和负载构成。14.The primary concern of electrical engineering is the doing of work by the delivery
15.Magnets have characteristics similar to electric charges in that like magnetic doles
repel each other and unlike magnetic doles attract each other.
1.It is believed that oil is derived from marine plant and animal life.
2.The application of the innovative design makes the electric machine become
smaller and more efficient.
3.Such materials are characterized by good insulation and high resistance to wear.
4.Gases differ from solids in that the former have greater compressibility than the
5.The new equipments feature wide working low voltage operation and high
6.The function of a fuse is to protect the circuit.
7.The new equipments provide a relatively small loss of energy.
8.The energy transmission in a thermal power plant mostly relates to thermal energy
9.Hydroelectric stations offer quite a number of advantages over their thermal and
10.When a spring is tightly stretched, it is ready to do work.
11.Aluminum remained unknown until the nineteenth century, because nowhere in
nature is it found free, owing to its always being combined with other elements, most commonly with oxygen, for which it has strong affinity.
12.The close spacing of conductors and the presence of solid insulation between them
results in the capacitance of cables being much greater per unit length than that of overhead lines.
13.Great efforts will be made to achieve advancement and independent innovation of
technology, which will lead to improved safety and cost-efficiency of nuclear power reactors and competitiveness of nuclear power.
14.When you use a computer to process information, you must have input, which is
the data you will deal with; you must process the data, which is the act of doing something with data according to instructions, and you must have output, which is the result of your processing.
15.Thermal power plants are those which make use of fuels like coal, petroleum and
16.Newton created a planetary dynamics which was so successful that for many years
scientists complained that nothing was left to be done.
17.The equivalent circuits, being descriptive and simple , are very useful for the
solution to a number of problems.
18.Wherever conductors are needed, insulators will be indispensable.
19.Animals, although they need some inorganic food, cannot live on it alone.
20.The progress study of thermodynamics is such that experts can predict which
processes or reactions might occur spontaneously.
21.The advantage of rolling bearing is that they cause less friction.
22.There is little doubt that human beings and computers are getting more friendly.
23.Obviously there was little probability that they would succeed in electrolysis.
24.Scientists have already known that under the extreme temperatures, say 260℃,
metal pre-sent zero resistance, that is, superconductivity of metal.
25.The principal objection to arc lighting was its high intensity, making it unsuitable
for most indoor applications.
1.The airplane is supported by the wings; it is propelled by the power plants; it is
guided by its control surfaces.
2.The test instrument is joined to the circuit with the help of a fuzzy control the
concepts presented here need not be implemented starting from scratch.
3.It should be noted that increasing the length of the wire will increase its resistance.
4.But for friction, the driving wheel would not run the belt, neither would the belt
run the wheel to be driven.
5.Not only should every machine get frequent lubrication, but each part should have
the right kind of lubrication.
6.Should the current be cut off, coil would return to its original position.
7.Set an object in motion, and it will keep on moving because of its inertia.
8.There was expected to be a radial electrostatic field near the earth’s surface.
9.If the resistance of the circuit is high, the current will decrease rapidly, but a high
induced e.m.f. will result.
10.Since 1964, Alcan has been digital computers to help control and optimize the
output of its various processes.