People had thought of building spacecraft several hundred years ago. They had thought of going to the moon and many other planets. Papers on spacecraft can be found among the papers of famous scientist who lived centuries ago. However, the craft could not be built until after World War II.
It is not easy to build a spacecraft. A spacecraft needs a good rocket that is strong enough to send it to outer space. Such a motor was not developed until
A spacecraft also needs as many as rend million very sophisticated parts. These parts are needed so that the craft can function well when it is flying far away from earth. These parts must have very high precision elements. Each of them must have the right shape and the right size. Such parts could not be mode until after
Today, spacecraft are being made all the time. They have to be enough to carry astronauts into outer space. What does a spacecraft look like? A spacecraft usually consist of three rockets that are joined together. The three rockets are called stages. The first stage takes the spacecraft to a certain speed and then falls away. The second stage takes it to speed twice as great as the first, and then it also falls away. The third stage takes the spacecraft to its top speed of more than 38,600 kilometers per hour.
Where is the place for the astronauts? It is at the top of the spacecraft. In the nose of the third stage a capsule. In this capsule are the astronauts and the instrument package. This capsule is actually the smallest part of the ship. But all sorts of very sophisticated instruments are found into his capsule. This little capsule is the most important part of the ship.
Each spacecraft usually has three rockets that are called
The function of the rockets is fund in paragraph ...
Which of the following statement is right?
A. Spacecraft have been built since 1994
B. All the three stages have the same speed
C. Out of the three stages, the first it the fasts
D. The firs rocket falls away as soon as it is air bone
E. The most important part of the craft is where the astronauts are
How fast is the second rocket? It is ... A. half of the first
B. faster than the third
C. as fast as the first
D. double the speed of the first
E. the fastest of the three rockets
A spacecraft also needs as many as ten million very
sophisticated parts. The underlined word means ... A. Big
B. Good C. Strong D. Simple
The word "marine" comes from the Latin word "mare1 which means "sea". Marine life means all the animal and plant species that live in the waters of the sea.
The geography of the seabed, the floor of the sea, is not so different from that of the land. There are hills, high mountains, valleys, rolling plains and plateaus. Below the low tide mark, the bottom of the sea slopes gently down word to a depth of about 100 fathoms, in the form of a shelf know as the continental shelf.
On the surface of the sea there are tiny floating plants and animals, including the eggs and young of larger animal and jellyfishes that are called "plankton". The plankton is important because a great many fishes feed on it. Several kinds of animal such as crabs, lobsters, shrimp, squids, octopuses, mollucsc (shellfish of all kinds), anemones and sponges live on the seashore. Such animal can also be found on the continental shelf, but the animals that live in the deeper waters are usually larger.
Seaweeds live in the shallow waters, not deeper than 50 fathoms as they need fairly strong sunlight to assimilate their food. In China and Japan seaweeds are
eaten: ill europe carrageen is used for thickening soup
and making jellies.
The really deep sea is cold and dark because the sunlight cannot penetrate the depths. The pressure in the deep sea higher than in the shallow water, and the
fishes are much more fragile and delicate in appearance than| those from parts of the sea where the pressure is lower; Some have large eyes and can see, but other are completely blind.
We should look on the sea as a valuable source food. Fishing industries should know the location of 1 fish they are trying to catch, and how .many can be caught without killing off the whole species.
Plankton is layer of tiny animal and plants that live on
B. floor of the sea
C. bottom of the sea D. surface of the sea E. continental shelf
"... as they need fairly strong sunlight ..." (paragraph 5)
The word 'they' refers to ... A. waters
C. fathoms D. sponges E. seaweeds
The description of the bottom of the sea is fund in
paragraph ... A. One
C. Three D. Four E. Five
Which of these statement is true according to the text? A. Seaweeds can live without sunlight
B. Marine life means everything found in the sea
C. Tiny floating plants live in the deep sea
D. Sunlight can penetrate the very deep sea
E. The geography of the seabed is similar to that of the land
The plankton is important because a great many fishes feed on it. (paragraph 3)
The underline word means ...
Hydroponics is the term used to describe the several ways in which plants can be raised without soil. These methods, also known generally as soilles gardening include raising plants in containers filled with water or any of other nonsoil mediums - including gravel, sand vermiculite and other more exotic medium, such as crushed rock or bricks, and shards of cinder blocks.
There are several excellent reasons for replacing soil with a sterilize medium. Soil-borne pests and
diseases are immediately elimated, as weeds are. And
the labour involved is reduced.
More important, raising plants in a nonsoil medium will allow you to grow more plants in limited amount of space. Food crops will mature more rapidly and produce greater yields. Water and fertilizer are conserved, since they can be reused. In addition hydroponics allow you to exert greater control over your plants, to insure more uniform results.
All of this is possible by the relation of a plant with it's growing medium. It isn't soil that plants need- it's the reserves of nutrients and moisture contained in
the soil, as well as the support the soil renders the
plant. Any growing medium will give adequate support.
The methods of hydroponics gardening developed over the past forty-five years can be divided into categories defined by the medium in which the plant
are grown. In water culture, the plants are grow only in
water, or in a water and nutrient solution. Sand culture calls for raising, plants in sterile sand, into which a water and nutrient solution is pumped. Aggregate culture replaces the sand, instead of using one of the materials such as gravel or vermiculite, and retaining the method of pumping a water and nutrient solution into the material. Finally, there are number of experimental or unorthodox techniques.
Hydroponics units have been used to replace the conventional benches in a green house, and soil-borne pests and diseases are avoided.
Why is hydroponics knows as soil less gardening?
A. Plants can only be raised in soil
B. Plants can be raised without soil
C. Soil in the garden needs much water
D. Garden is not provided by nonsoil medium
E. Crushed rocks or bricks are hard for plants
What must be given regularly to the plants raised in
hydroponics units? A. Gravel and sand B. Sand and bricks
C. Water and fertilizer
D. Sand and vermiculite
E. Crushed rocks and bricks
Food crops from hydroponics can be harvested earlier
This information is found in paragraph ... A. 2
Which of the following statements in correct according to the text?
A. Water and fertilizer cannot be raised
B. Soil-borne pests develop in hydroponics
C. Raising plants in a nonsoil medium is impossible
D. Plants are categorized according to their containers
E. Hydroponics gardening can be operated in limited space
Soil-borne pests and diseases are immediately eliminated (paragraph 2)
The underline word means ...
A. handled B. removed C. stopped D. destroyed E. developed
THE SUN AS A SOURCE OF ENERGY
As the supplies of fossil fuels-coal, oil and gas are running out, scientists have been working hard trying to find ways of obtaining other kinds of fuel. They have succeeded in finding one that is very efficient; nuclear fuel, However, the ores which produce this in of energy, e.g. uranium ores, will eventually run out, too. Fortunately a source of abundant energy, which is virtually inexhaustible-sunlight-has been waiting for the scientist.
The sun sends out energy equal to that produced by 10,00 million tons of coal every second, of which the earth receives only one two-billionth part. It is estimated that the energy which falls no one square matre of the earth's surface per second can be used to keep about seven 100 watt lamps burning. The sun's energy is really abundant, but only a limited amount has so far been used by man. The sun can also used as
a source of fuel for power plants. Such power plants are still in the experimental stages.
However, it is hoped that they will lead the way to a wider use of solar energy to run machines.
Solar energy can be used in telephone
communications, space technology, and farming. Solar batteries have been in experimental use for a number of years to power telephone lines. They are now being used to recharge batteries which power instruments used in space vehicles. Scientists have also succeeded in developing solar pumps that can raise water for irrigation.
The sun seems to be ideal source of energy for a great many uses. Yet to change the abundant sunlight into energy is a different matter. The instruments needed to catch the sun's energy are still very
.expensive. However, once man succeeds in catching even a small part of that energy, no body would worry about running out of fossil fuels or uranium ores.
It lines in the hands of the scientist to make this dream come true.
Why do people worry about oil and coal as sources of
energy? Because ...
A. they are decreasing in quality
B. they are very efficient kinds of fuel
C. they will run out in the course of time
D. they are inexhaustible sources of energy
E. there are abundant fossil fuels on the earth
"Solar energy has been used in many different fields". This information can be found in paragraph ...
A. 1 and 2
B. 2 and 3
C. 3 and 4
D. 4 and5
E. 5 and 3
Find out the statement which is not correct according to the text
A. There is plentiful of solar energy
B. Uranium ores produces nuclear energy
C. Solar energy can be used in telephone communications
D. The instrument for catching the sun energy has already been widely developed
E. Fossil fuels are estimated to be running out
They have succeeded in finding one that is very efficients ; nuclear fuel, (paragraph 1)
'one' refers to ...
A. oil B. gas C. ore D. fuel E. coal
".... e.g. uranium ores, will eventually run out, too." (paragraph 1)
The underlined word means ... A. slowly
C. finally D. exactly E. virtually
Which statement is true according to the text?
A. The function of an electric meter is to check?
The electric current supplied to your home from the power station is alternating current, or AC for short. AC reverses its direction of flow 100 times, every second. It flows 50 times in one direction. AC is easier to generate and to transmit than DC (direct current). Another reason that AC is used for domestic power supplies is that its voltage can changed by a device called a transformer.
Huge quantities of electrical energy are produced by a power station. AH this electricity must be sent out
across the country to houses, shops, and factories. To
'push' the electricity out over long distances, very high voltages are needed. However, when the electricity reaches it's destination, lower voltages are needed because high voltages are very dangerous.
High voltages are 'stepped-down' by means of a transformer, an invention of the nineteenth-century English scientist Michael Faraday, who also discovered the principle of the dynamo. (The dynamo can change mechanical energy into electrical energy). The transformer consists of two coils of wire than the other. If AC is passed through one coil, it induces moving
lines of magnetic force.
This is turn induces an electric current in the other coil. Suppose coil A has half as many turns as coil B, then the voltage induced in it will be half the voltage in coil B. in this way the voltages can be reduced. At the same time the current can be increased.
The power supply from the power station is stepped-down by transformers from hundreds of
thousands of volts to 220 volts for domestic use.
Houses are wired with electric circuits. Electricity coming into the house passed through a meter, which measures the amount of electricity used, so that the supplier can charge for it. The current also passes through a fuse box. A fuse protects electrical appliances from overloading. If too much power is taken, a wire in the fuse gets hot and melts, so breaking the circuit and acting as a 'switch'.
The electric energy supplied to our houses is from a ... A. Fuse box
C. Power station
D. Electric meter
E. Electrical appliance
A transformer is used to ... A. Produce electric energy
B. Protect an appliance from getting too hot
C. Change the voltage of an electric current
D. Indicate how much electricity has been used
E. Change direct current into alternating current
whether there is an electric current or not
B. The electric current which goes into house is?
changed into direct current first
C. The electric current which comes from a power plant is alternative current
D. The amount of electricity that is used can be seen in a fuse box
E. A fuse will function when electrical appliances are overloaded
What device did Michael Faraday discover? A. The fuse
B. The generator
C. The transformer
D. The electrical meter
E. The electrical appliance
AC is easier to generate and to transmitthan direct
The underlined word above means to ... A. flow
C. induce D. supply E. change
After taking off, the plane continues to ascend until it reaches an altitude of 25,000 feet.
The opposite of the word 'ascend' is to ... A. go down
B. run down
C. fall down
D. come down
E. climb down
Ii) Europe the temperature in each ... differs greatly
A. Cycle B. Season C. Climate D. Weather
Forest is a valuable natural resource; that's why we should ... it.
B. Destroy C. Neglect D. Conserve
If the space crew land on the surface of the moon, they will experience the gravity exertedby the moon.
The underlined word means ... A. put
E. thrown away
Too many people means that pure water is becoming
scarce in many areas.
The antonym of the underlined word is ... A. rare
C. strange D. plentiful E. sufficient
Through ecology, we try, to ... the balance in the ecological system.
B. Adapt C. Release D. Restore