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单选题
According to the information given in the passage, if two20-year-old twins lived on earth, and one of them left on a journey for Alpha Centauri at very close to the speed of light, then managed to survive the journey and return to earth having aged 40 years during the journey, what could she expect to find upon her return to earth?
A
Her great-grandmother
B
Her twin at the age of 20
C
Her twin at the age of 40
D
Her twin at the age of 60
E
Her twin’s great-grandchildren
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参考解析
解析：
推断题。根据文章第二段“If Mr. Einstein was right about relativity. . . then time slows down when you approach the speed of light. A person traveling at any velocity near the speed of light will age only days for every week, month, or even year that passes on earth.”一句可知，E项是正确的。
推断题。根据文章第二段“If Mr. Einstein was right about relativity. . . then time slows down when you approach the speed of light. A person traveling at any velocity near the speed of light will age only days for every week, month, or even year that passes on earth.”一句可知，E项是正确的。
更多 “单选题According to the information given in the passage, if two20-year-old twins lived on earth, and one of them left on a journey for Alpha Centauri at very close to the speed of light, then managed to survive the journey and return to earth having aged 40 years during the journey, what could she expect to find upon her return to earth?A Her great-grandmotherB Her twin at the age of 20C Her twin at the age of 40D Her twin at the age of 60E Her twin’s great-grandchildren” 相关考题
考题
There are two types of twins: identical and non-identical twins. Identical twins are formed from a single egg in mother's body which divides to form. two separate babies. Identical twins look the same and are often dressed by their parents in clothes of the same colors. It is often difficult to tell identical twins from each other, even when they are standing side by side. Non-identical twins come into being when the mother produces two separated eggs at the same time, both of which grow to form. babies. In this case the twins look like normal brothers and sisters and are easy to tell one from the other.In the 1970s and 1980s a scientist did some research into twins. He invited many pairs of identical twins to university and asked them to take part in a week of tests. He was particularly interested in adopted (收养) twins who had been separated at birth. He would give the twins different kinds of tests to study their speed of thinking, their speech, their memory, the ways they saw and heard different things, and so on. Time and time again he found separated twins who preferred clothes of the same color, used the same kind of shaving soap, wore the same shaped square glasses and the same colored socks.There is a third type of twins, but it is a very unusual one. Twins who are joined together at birth are known in western countries as Siamese twins.(1)It is difficult to tell identical twins because ____________.A、they are dressed in the same clothesB、they are dressed in the same colorC、they are very alikeD、they are standing side by side(2)If the twins are easy to tell from each other, they are ____________.A、very probably non-identical twinsB、surely non-identical twinsC、surely identical twinsD、always a brother and a sister(3)Which of the following is NOT true according to this passage?A、In the 1970s and 1980s a scientist did some research into the two main types of twins.B、In the week of tests, he tested their speed of thinking, their speech, their memory and some other things.C、There were twins who had been separated from each other as soon as they were born.D、Very often, separated twins were found to choose things of the same kind, the same shape and the same color.(4)According to the passage, how many types of twins are there actually?A、oneB、twoC、threeD、four(5)This passage mainly tells us ____________.A、the main types of twinsB、what has been found out about twinsC、how twins are formedD、how a scientist studied twins
考题
If there were life on Mars, such life forms( )unable to survive on earth.
A、isB、areC、would beD、will be
考题
AWhen you look at the sky at night，the moon looks bigger than the stars． In fact，the moon is much smaller than the stars．It is much smaller than the earth． But the moon is much closer to us than any star． That is why it looks so big． If you hold a coin close．to your eye，it looks big．If you look at it across the room，it looks small．The moon moves around the earth． It makes one trip in about four weeks． The moon looks flat(扁的)to us． But it is a round ball，like the earth．People once thought the moon had fire(火) on it． They thought the fire made it bright．Now we know the moon is like a mirror( 镜子 )． It gets its light from the sun Our sunlight comes from the sun，too: What is the sun? The sun is star． The stars we can see have their own light． There are many big stars we can-t see． Their light has burned out． Others are still bright，but they are so far away that we can-t see them． The sun looks bigger and much brighter than other stars because it is the nearest of all stars． The sun and the other stars we see are very hot，but the air around us saves us from(使------免于) the heat(热量) of the sun．The sun gives us light and warmth．It makes plants grow and leaves turn green． It makes life possible on our earth．It is a life-giving star．( )21． The moon looks bigger because__________ ．A． some stars are smaller than itB．it is between the sun and the earthC．it is the closest to the earthD．it is very bright
考题
According to the passage, the earth in its very early period was ______.A. in molten stateB. in water stateC. in rock stateD. a vast ocean
考题
It can be learned from the passage that about four billion years ago ______.A. the earth was in molten stateB. the earth surface temperature was above 100℃C. the earth surface temperature was below 100℃D. rain water could remain on the earth
考题
According to the passage, which is true about the ocean?A. The waters of the ocean came from rain water.B. The ocean was formed from the, lighter rock materials.C. The vast single ocean formed about 200 million years ago.D. The ocean covered the whole surface of the earth at very beginning.
考题
All the other five planets ________.[A] always appear near the path of the sun[B] are moving in a way more complicated than the earth does[C] aren't moving around the sun as independently as the earth does[D] are moving around the sun at the same speed as the earth does
考题
One day on the moon is _____.A. two Earth week longB. two Earth weeks longC. two Earth weeks longerD. two Earth weeks length
考题
The computer works very fast, _________ data at the speed of light.
A.having handledB.handlingC.handledD.handles
考题
共用题干
Weight on and off the Earth We are so used to.our life on the surface of the earth that it can be quite an effort for our mind to break free of all the ideas that we take for granted.Because we can feel that things are heavy,we think of "weight"as being a fixed quality in an object,but it is not really fixed at all.If you could take a one-pound packet of butter 4,000 miles out from the earth,it would weigh only a quarter of a pound. Why would things weigh only a quarter as much as they do at the surface of the earth if we took them 4,000 miles out into space?The reason is this:all objects have a natural attraction for all other objects;this is called gravitational attraction.But this power of attraction between two obects gets weaker as they get farther apart.When the butter was at the surface of the earth,it was 4,000 miles from the center.When we took the butter 4,000 miles out,it was 8,000 miles from the center,which is twice the distance.If you double the distance between two objects,their gravitational attraction decreases two times two.If you treble the distance, it gets nine times weaker(three times three)and so on. So this is one of the first things we need to remember that the weight of an object in space is not the same as its weight on the surface of the earth. What about the weight of our pound of butter on the surface of the moon?At the distance the puii of the earth is about 4,000 times smaller than it is here on the surface,so we can forget all about the earth-pull on our butter. On the other hand,on the moon there will be an attraction between the butter and the moon,but the butter will weigh only about one-sixth as much as it does on the earth.This is because the moon is so much smaller than the earth.The amount of gravitational pull that a body produces depends on the amount of material in it.A packet of butter has a gravitational pull of its own;but this is very small in relation to the pull of something as large as the moon,or the earth,or the sun.According to the passage,"weight"should be understood in the sense thatA:it is fixed if it is outside the earth's gravitational puliB:it decreases four times when it is 4,000 miles from the earth's centerC:it varies with the change of the gravitational attraction between two objectsD:things increase in amount as they are closer to the earth's surface
考题
单选题According to the passage, the Earth’s magnetic field has _____.A
begun to change in the opposite directionB
been weakening in strength for a long timeC
caused the changes on the polaritiesD
misguided many a man and animal
考题
单选题The type of fog that occurs on clear nights with very light breezes and forms when the earth cools rapidly by radiation is known as（）.A
Radiation fogB
Frontal fogC
Convection fogD
Advection fog
考题
单选题Diurnal aberration is due to（）.A
motion of the Earth in its orbitB
rotation of the Earth on its axisC
the body's orbital motion during the time required for its light to reach the EarthD
a false horizon
考题
单选题According to this passage, some people believe that eventually _____.A
human societies will be much more cooperativeB
man will live in a highly organized worldC
machines will replace manD
living beings will disappear from Earth
考题
单选题According to this passage, some people believe that eventually______.A
human societies will be much more cooperativeB
man will live in a highly organized worldC
machines will replace manD
living beings will disappear from Earth
考题
单选题According to the passage, atmospheric carbon dioxide performs all of the following functions EXCEPT: _____.A
absorbing radiation at visible wavelengthsB
absorbing infrared radiationC
absorbing outgoing radiation from the EarthD
helping to retain heat near the Earth’s surface
考题
单选题According to the passage, _____.A
we should not worry about the transition of the Earth’s magnetic fieldB
the Earth’s magnetic field will not change for at least 2000 yearsC
the Earth’s magnetic field has decreased its strength rapidlyD
the transition of the Earth’s magnetic field can be controlled by modern science
考题
单选题A mean sun is used as the reference for solar time for three reasons. Which reason is NOT a cause for use of a mean sun?（）A
The motion of the apparent sun is along the eclipticB
Measurement of time is along the celestial equatorC
The speed of the Earth's revolution is not constantD
There are variations in the Earth's rotational speed
考题
单选题According to the passage, the root cause for weather changes on the earth is ______.A
the atmosphere surrounding the earthB
water from oceans and lakesC
energy from the sunD
greenhouse gases in the sky
考题
单选题Without the sun’s light ______ the earth’s surface, it would be so cold that life could not exist on the earth.A
warmsB
warmedC
warmingD
to warm
考题
单选题According to the passage, all the following statements are TRUE EXCEPT that_____.A
a completion process will be held to select the four astronautsB
the cost of Mars One could go as much as $6 billionC
if it goes as planned, we could expect to watch Mars One on TVD
the four astronauts could return to Earth after a few years' stay on Mars
考题
单选题How can we remember things more easily according to the woman?A
By connecting them with a physical object.B
By looking at them very carefully first.C
By having people remind US of them.
考题
单选题The best title of the passage may be “______”.A
Bike RidersB
A Special CountryC
Bike TaxisD
A Cheap Journey
考题
单选题Planetary aberration is due，in part，to（）.A
refraction of light as it enters the Earth's atmosphereB
rotation of the Earth on it's axisC
the body's orbital motion during the time required for its light to reach EarthD
a false horizon
考题
单选题According to the passage, which of the following will present the most difficult challenge for humans attempting interstellar space travel?A
Achieving velocities near the speed of lightB
Withstanding the acceleration necessary for traversing interstellar distancesC
Maintaining clean air and water on a journey that could last centuriesD
Accommodating the effects of relativistic time dilationE
Enabling the humans on board to survive during the journey
考题
单选题It can be concluded from information contained in the passage that the average temperature at an altitude of 1 kilometer above the Earth is about _____.A
15℃B
9℃C
2.5℃D
-12℃
考题
单选题As you approach Old River Control Structure Light you see a flashing amber light. You should（）.A
navigate as close to the left descending bank as safety permitsB
navigate as close to the right descending bank as safety permitsC
turn into the inflow channel as the bypass is now openD
slow your engine speed to not more than 5 mph
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