题干

   A calorie is a unit of energy, not a measure of weight or nutrient density. The calories you see on nutrition labels,however,are actually kilocalories. The calories on food packaging always refer to kilocalories, even though it just says “calories”. One kilocalorie is the amount of energy required to heat 1 kilogram of water by 1 degree Celsius. Calories in our food all come from one of the three nutrients: fats, carbohydrates and proteins.

In 1990, the U. S. government passed the Nutrition Labeling and Education Act, which means that before any packaged food in the U. S. hits the shelves, food scientists have to measure its nutrients and calories. One way to do this is using a tool called bomb calorimeter(弹氧热卡计). This tool directly measures the amount of energy that a food contains. To use this tool, scientists place the food in question in a sealed(密封的)container surrounded by water and heat it until the food is completely burned off. Scientists then record the rise in water temperature to determine the number of calories in the product.

Food scientists also rely on a calculation developed by the 19th-century U. S. chemist Wilbur Olin Atwater to indirectly estimate the number of calories in food products. Calorimeters don’t take into account that humans lose some calories through heat and feces(类便). Atwater’s experiments found that proteins and carbohydrates each have about 4 calories per gram and fats have 9 calories per gram.

However, some experts say that the Atwater system is outdated and inaccurate. A 2012 study found that the energy content of certain foods, such as nuts, could not be accurately calculated by the Atwater system. Besides, it does not take into account the digestive process, but assumes the complete conversion of nutrients to energy.

【小题1】What can we learn about the unit of energy on nutrition labels?
A.It actually means calories.
B.It refers to kilocalories.
C.It reads kilograms.
D.It employs degrees.
【小题2】What should be done to measure the amount of calories according to the calorimeter?
A.Heat the food in an open container until the food is completely burned off.
B.Take the calories through heat and feces into consideration.
C.Learn the calculation developed by Wilbur Olin Atwater.
D.Calculate the amount of energy in food products directly.
【小题3】How many calories does a food containing 10 grams of proteins and 5 grams of fats have according to the Atwater system?
A.About 40.B.About 45.
C.About 85.D.About 130.
【小题4】What would be the best title for the text?
A.How Are Calorie Counts Calculated?
B.Where do Calories Come from?
C.Can Nutrients Be Converted to Energy Totally?
D.Nutrients and Calories Listed on a Food Label
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同类题1

   The idea of being able to walk on water has long interested humans greatly. Sadly, biological facts prevent us ever accomplishing such a thing without artificial aid---we simply weigh too much, and all our mass pushes down through our relatively small feet, resulting in a lot of pressure that makes us sink.

However, several types of animals can walk on water. One of the most interesting is the common basilisk Basilicus basilicus, a lizard (蜥蜴)native to Central and South America. It can run across water for a distance of several meters, avoiding getting wet by rapidly hitting the water’s surface with its feet. The lizard will take as many as 20 steps per second to keep moving forward. For humans to do this, we,d need huge feet that we could bring up to our ears in order to create adequate w hitting. ’’

But fortunately there is an alternative : cornflour. By adding enough of this common thickening agent to water (and it does take a lot), you can create a “non-Newtonian” liquid that doesn’t behave like normal water. Now, if the surface of the water is hit hard enough, particles(粒子)in the water group together for a moment to make the surface hard. Move quickly enough and put enough force into each step, and you really can walk across the surface of an adequately thick Liquid of cornflour.

Fun though all this may sound, it’s still rather messy and better read about in theory than carried out in practice. If you must do it, then keep the water wings handy in case you start to sink--and take a shower afterward!

【小题1】Walking on water hasn’t become a reality mainly because humans______.
A.are not interested in it
B.have biological limitations
C.have not invented proper tools
D.are afraid to make an attempt
【小题2】What do we know about Basilicus basilicus from the passage?
A.It is light enough to walk on water.
B.Its huge feet enable it to stay above water.
C.It can run across water at a certain speed.
D.Its unique skin keeps it from getting wet in water.
【小题3】What is the function of the cornflour according to the passage?
A.To create a thick liquid.
B.To turn the water into solid.
C.To help the liquid behave normally.
D.To enable the water to move rapidly.
【小题4】What is the author’s attitude toward the idea of humans’ walking on water?
A.It is risky but beneficial.
B.It is interesting and worth trying.
C.It is crazy and cannot become a reality.
D.It is impractical though theoretically possible.

同类题2

   Storing food is common in members of the crow family. A new study tested the birds outside for this naturally occurring behavior, which may have evolved(进化)specifically because it gives crows a survival advantage. Some crow species are known to naturally use tools to recover food. So the researchers tested whether the birds could store and recover a tool so they could use it to find their food after a gap of 17 hours — something we wouldn’t expect them to do naturally. But they were able to instantly select the tool out of a number of unnecessary items.

In another experiment, the researchers taught crows to select a token(礼品券)from a number of items so that they could then exchange it for food. Again, the birds then showed that they could plan for the future using this new behaviour. This is different from all of the previous studies in future planning, which have focused on naturally occurring behaviour. For example, we know that chimpanzees select, transport and save appropriate tools for future needs.

These studies have shown that animals can plan for the future — but they leave an important question open for debate. Are animals only able to plan to use abilities that have evolved to give them a specific advantage, or can they flexibly and intelligently apply planning behaviour across various actions? Most critics would say the former, as the animals were tested in naturally occurring behaviour.

But the new research provides the first evidence that animal species can plan for the future using behaviour that doesn’t typically occur in nature. This supports the view that at least some recognitive(认知的)abilities in animals don’t evolve just in response to specific problems. Instead, it suggests that animals can apply these behaviour flexibly across problems in a similar way to humans. We need to study how flexible behaviour evolved. Then we might be able to see how crows’ ability to plan for the future fits in with their broader cognitive powers.

【小题1】What’s the new finding about some crows according to Paragraph 1?
A.They can store food.B.They can use tools to recover food.
C.They can store and recover tools.D.They can select and store food.
【小题2】What are crows trained by researchers to do when given a token?
A.Reject it casually.B.Exchange it for food.
C.Save it as their food.D.Build a nest with it.
【小题3】What can we infer about the studies that animals can plan for the future?
A.They are debatable.B.They are disappointing.
C.They are logical.D.They are convincing.
【小题4】What can be learned about flexible behaviour in animals?
A.It develops only with age.B.It is unclear how it evolved.
C.No animals but crows benefit from it.D.It helps plan for the future.

同类题3

Things Your Pilot Won't Tell You
You may not be getting the airline you paid for.
You may go to an airline website and buy a ticket, and get onto an airplane that has a similar name painted on it, but half the time, you're really on a regional (地方的) airline.The regionals aren't held to the same safety standards as the majors: their pilots aren't required to have as much training and experience, and the public doesn't know that.
—Captain at a major airline
If you're a nervous flier, book a morning flight.
The heating of the ground later causes bumpier (颠簸的) air, and it's much more likely to thunderstorm in the afternoon.
—Jerry Johnson , pilot, Los Angeles
The smoothest place to sit is often over or near the wing.
The bumpiest place to sit is in the back.If you're in the middle, you don't move as much.
—Patrick Smith, pilot, and author of Cockpit Confidential
Sit in the front if you want fresher air.
The general flow of air in any airplane is from front to back.So if you're really concerned about breathing the freshest possible air or not getting too hot, sit as close to the front as you can.Planes are generally warmest in the back.
—Tech pilot at a regional airline, Texas
You never know where the safest seat is.
There is no safest place to sit.In one accident, the people in the back are dead; in the next, it's the people up front.
—John Nance, aviation safety analyst and retired airline captain, Seattle
I've been struck by lightning twice.
Most pilots have.Airplanes are built to take it.You hear a big boom and see a big flash and that's it.You're not going to fall out of the sky.
—Charlotte, pilot for a regional earner,.North Carolina
People don't understand why they can't use their cell phones.
Well, what can happen is 12 people will decide to call someone just before landing, and I can get a false reading on my instruments saying that we are higher than we ideally are.
—Jim Tilmon, retired American Airlines pilot, Phoenix
【小题1】Jerry Johnson advises nervous fliers to ______.
A.sit in the back
B.fly in the morning
C.fly with major airlines
D.avoid flying in bad weather
【小题2】The best seats for those who need fresh air are ______.
A.in the frontB.in the middle
C.in the backD.near the wing
【小题3】Passengers' use of cellphones before landing is likely to ______.
A.increase the risk of being struck by lightning
B.make it difficult for pilots to control the plane
C.cause the instruments of the plane to break down
D.affect pilots' judgment about the height of the plane

同类题4

   When we are in a bad mood or ill at ease, as long as we listen to a beautiful song, we will feel better and relaxed. A musical _____ always makes us comfortable. By listening to music, we also can understand the philosophies which _____ the music.

Music not only can change our moods, but also can _____ some kinds of diseases, such as insomnia (失眠). Music treatment has been _____ in many countries recently. It has been _____ that music can make people relaxed, more _____ and have a better sleep. Some music even can promote us to _____ a certain number of natural chemicals from our bodies. Besides, music also has a good effect on strengthening people’s memory. In a university, 60 girl students accepted a (n) _____ , It showed that the girls who received musical training in their childhoods could _____ 17% more reading materials than those who didn’t. Some experts also ______ that musicians’ left brains are bigger in size than ordinary people’s. As we know, our memory is ______ by the left brain. That might be the reason why those who receive musical training have a better memory. ______ , the patients whose speaking is damaged may recover ______ by listening to or appreciating some music.

In addition to these ______, music can also promote children’s intelligence growth and ______ people's life. In some countries, people conducted a (n) ______ experiment. They played music beside vegetables and cows. As a result, the vegetables grew faster and the cows produced more milk. Why does music have so many magical functions? ______ , music influences people in psychological and physical ways.

From a psychological angle, music can impact directly on people's moods and behavior. Music has various rhythms, and so do human beings. When the two kinds of rhythms are in ______, the former can adopt the latter’s psychological rhythms. Usually, people will ______ music’s rhythms to change their movements.

From a physical angle, music is a sound wave which has a range of frequency. The wave can have ______ on people’s every neuron, which can secrete (分泌) some chemicals that are good for our health

【小题1】
A.conditionB.educationC.contextD.training
【小题2】
A.consist ofB.lie inC.belong toD.center around
【小题3】
A.treatB.causeC.preventD.settle
【小题4】
A.forbiddenB.demandedC.reformedD.adopted
【小题5】
A.provedB.suggestedC.recognizedD.estimated
【小题6】
A.intelligentB.mercifulC.energeticD.enthusiastic
【小题7】
A.repeatB.reduceC.releaseD.reject
【小题8】
A.examinationB.surveyC.programD.invitation
【小题9】
A.rememberB.imagineC.acceptD.understand
【小题10】
A.realizedB.revealedC.predictedD.recommended
【小题11】
A.possessedB.influencedC.unitedD.controlled
【小题12】
A.HoweverB.FurthermoreC.StillD.Therefore
【小题13】
A.suddenlyB.slightlyC.graduallyD.regularly
【小题14】
A.functionsB.principlesC.secretsD.keys
【小题15】
A.broadB.extendC.expandD.stretch
【小题16】
A.interestingB.ridiculousC.practicalD.scientific
【小题17】
A.In generalB.In factC.In contrastD.By comparison
【小题18】
A.useB.workC.harmonyD.conflict
【小题19】
A.changeB.followC.recordD.adapt
【小题20】
A.pressureB.cautionC.effectD.Progress

同类题5

Are some people born clever, and others born stupid? Or is intelligence developed by our environment and our experience? Strangely enough, the answer to these questions is yes. To some extent our intelligence is given to us at birth, and no amount of education can make a genius out of a child born with low intelligence. On the other hand, a child who lives in a boring environment will develop his intelligence less than one who lives in rich and varied surroundings. While the limits of a person’s intelligence are fixed at birth, whether or not he reaches those limits will depend on his environment. This view, now held by most experts, can be supported in a number of ways.
It is easy to show that intelligence is to some extent something we are born with. The closer the blood relationship between two people, the closer they are likely to be in intelligence. Thus if we take two unrelated people at random(随机地) from population, it is likely that their degrees of intelligence will be completely different. If, on the other hand, we take two identical twins, they will very likely be as intelligent as each other. Relations like brothers and sisters, parents and children, usually have similar intelligence, and this clearly suggests that intelligence depends on birth.
Imagine now that we take two identical twins and put them in different environments. We might send one, for example, to a university and the other to a factory where the work is boring. We would soon find differences in intelligence developing, and this indicates that environment as well as birth plays a part. This conclusion is also suggested by the fact that people who live in close contact with each other, but who are not related at all are likely to have similar degrees of intelligence.
【小题1】Which best describes the writer’s point in Para.1?
A.Intelligence is given at birth.
B.Intelligence is developed by the environment.
C.Intelligence is fixed at birth, but is developed by the environment.
D.Some people are born clever and others born stupid.
【小题2】It is suggested in this passage that __________.
A.close relations usually have similar intelligence
B.unrelated people are not likely to have similar intelligence
C.the closer the blood relationship between people, the more different they are likely to be in intelligence
D.people who live in close contact with each other are not likely to have similar degrees of intelligence
【小题3】The example of the twins going to a university and to a factory separately shows_________.
A.the importance of their intelligence
B.the effect of environment on intelligence
C.the importance of their positions
D.the part that birth plays
【小题4】The best title for this article would be “_____________”.
A.On Intelligence
B.What Intelligence Means
C.Born with Intelligence
D.Environment Decides Intelligence