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However, some experts say that the Atwater system is outdated and inaccurate.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

   About ten men in every hundred suffer from color-blindness in some way. Women are luckier: only about one in two hundred is affected on this matter. Perhaps, after all, it is safer to be driven by a woman!

There are different forms of color-blindness. In some cases a man may not be able to see deep red. He may think that red, orange and yellow are all shades of green. Sometimes a person cannot tell the difference between blue and green. In rare cases an unlucky man may see everything in shades of green — a strange world indeed.

Color-blindness in human beings is a strange thing to explain. In a single eye there are millions of very small things called "cones". These help us to see in bright light and to tell the difference between colors. There are also millions of "rods", but these are used for seeing when it is near dark. They show us shapes but no color.

Some insects have favorite colors. Mosquitoes(蚊子) prefer blue to yellow. A red light will not attract insects, but a blue lamp will. In a similar way human beings also have favorite colors. Yet we are lucky.

With the aid of the cones in our eyes we can see many beautiful colors by day, and with the aid of the rods we can see shapes at night. One day we may even learn more about the invisible colors around us.

【小题1】What is the passage mainly about?
A.Colors and their surprising effects.
B.Women being luckier than men.
C.Danger caused by color-blindness.
D.Color-blindness.
【小题2】What can we know about the color-blind?
A.Not all of them have the same problem in recognizing colors.
B.None of them can see deep red.
C.None of them can tell the difference between blue and green.
D.All of them see everything in shades of green.
【小题3】According to the passage, with the help of the cones, we can ______.
A.tell different shapes
B.see in weak light
C.kill mosquitoes
D.tell orange from yellow
【小题4】Which can we use to attract and kill mosquitoes?
A.Red light.
B.Yellow light.
C.Blue light.
D.Green light.

同类题3

   What’s your opinion on spicy food? Some people cannot handle even the smallest amount of chili peppers in their dinner while others can’t get enough of them.

Scientists have long been puzzled by why some people love the chili while others loathe it. Plenty of research has been done on the subject, dating as far back as the 1970s. Previous results showed that a love of chilies is related to childhood experiences, and that cultural influences affect our taste too. But the latest study has found that a person’s love of spicy food may be linked to his or her personality (性格) more than anything else, CBC News reported.

“We have always assumed that liking drives intake — we eat what we like and we like what we eat. But no one has actually directly bothered to connect personality with intake of chili peppers,” said Professor John E. Hayes from Pennsylvania State University, who led the study.

But before you look at the study, you should first know that “spicy” is not a taste, unlike sour, sweet, bitter and salty taste. It is, in fact, a burning feeling that you feel on the surface of your tongue. This got scientists thinking that maybe a love of spicy food is brought about by people’s longing for thrill, something they usually get from watching action movies or riding a roller coaster.

In the study, 97 participants, both male and female, were asked to fill out questionnaires about their personality, for example, whether they like new experiences or tend to avoid risks. They were then given a glass of water with capsaicin (辣椒素), the plant chemical that makes a chili burn, mixed into it.

By comparing the answers to the questionnaire and what participants said they felt about the spicy water, researchers found that those who tended to enjoy action movies or take risks were about six times more likely to enjoy the spicy water.

Interestingly, we used to believe that the reason why some people can withstand (耐受) spicy food is that their tongues have become less sensitive to it. However, this latest study has found otherwise. “It’s not that it doesn’t burn as badly, but that you actually learn to like the burning feeling,” Hayes explained.

【小题1】What’s the meaning of the underlined word “loathe” in the second paragraph?
A.Dislike.B.Fear.
C.Put up with.D.Adapt to.
【小题2】What did Professor John
A.Hayes and his team discover from their study?
B.What we eat actually helps to develop our personality.
C.Males are more likely to enjoy spicy food than females.
D.Those trying to avoid risks tend to be less interested in spicy food.
E.People are wrong to treat " spicy" as a kind of taste rather than a feeling.
【小题3】Why do some people like spicy food according to the recent study?
A.Because their taste has become less sensitive.
B.Because they love the burning feeling.
C.Because they want to challenge themselves.
D.Because the more they try spicy food, the less it burns.
【小题4】What’s the main idea of the passage?
A.What one likes to eat mainly depends on one’s personality.
B.Whether one enjoys spicy food depends largely on one’s personality.
C.One’s personal experiences have nothing to do with their taste.
D.Different people have different taste.

同类题4

   Do you like eating processed meat? If you do, think twice now if you want to eat such meat for the sake of your health.  Why? "It's because eating processed meat can cause cancer, " World Health Organization (WHO) experts said last Monday.

Processed meat is the meat that has been preserved by salting, smoking, drying or canning. Experts from the WHO's International Agency for Research on Cancer (IARC) in Lyon, France studied 800 patients.  The experts connected processed meat, such as hot dogs and bacon, with at least three kinds of cancer.  A person who eats 50 grams of processed meat per day— about two pieces of bacon— increases his or her risk of bowel (肠) cancer by 18 percent.

The IARC has included processed meat in its Group 1 list, for which there is " enough evidence" of its connection with cancer. Tobacco is also on the Group 1 list.

The experts also said red meat, including beef, lamb and pork, is "probably" carcinogenic (致癌的)to humans. Dr. Kurt Strait is with the IARC. He said in a statement that the risk of cancer increases with the amount of meat a person eats. Health experts in some countries advised people against eating large amounts of red and processed meat. But those suggestions had been centered on the increased risk of heart disease and obesity.

However, meat industry groups protest the result of the WHO's study.  They say that meat is part of a balanced diet.  They also say the causes of cancer are broad, and include environment and lifestyle factors.

The WHO's report cites (引证) the Global Burden of Disease Study's project, which shows that diets high in processed meat lead to 34, 000 cancer deaths per year worldwide.

【小题1】It can be inferred that the items on the Group 1 list of the IARC    .
A.are all processed foods
B.aren't often eaten by people
C.can be the most dangerous to humans
D.can greatly increase the risk of cancer
【小题2】Which can take the place of the underlined word "protest"?
A.Learn from.B.Disagree with.
C.Take interest in.D.Pay attention to.
【小题3】Which is the best title of the passage?
A.WHO: Processed Meat Can Cause Cancer
B.The Importance of Having a Balanced Diet
C.Eating Too Much Red Meat Is Bad for Humans
D.The Causes of Some Kinds of Cancer

同类题5

Amazing Benefits of Listening to Music

If you love listening to music, you’re good company. 【小题1】

★Music makes you happier.

When you listen to music, your brain produces a special matter. It biologically (生物学上) causes listeners to feel emotions like happiness, excitement, and joy. So next time you need an emotional increase, listen to your favorite tunes for 15 minutes.

【小题2】

Listening to music you enjoy reduces levels of the stress in your body. This is an important finding since stress causes many illnesses. To stay calm and healthy during a stressful day, turn on the radio.

★Music helps you sleep better.

A study showed that students listening to classical music for 45 minutes slept better than students who did nothing. If you’re having trouble sleeping, try listening to a little Bach or Mozart before bedtime.

★Music helps you eat less.

【小题3】If you’re looking for ways to reduce your appetite (食欲), try dimming the lights and listening to soft music next time you sit down for a meal.

★Music strengthens learning and memory.

Researchers discovered that music can help you learn and recall information better. 【小题4】 Memorize these results. You now have a strategy to study more effectively for your next test.

★Music raises IQ and school performance.

Research shows that taking music lessons predicts higher school performance and IQ in young children. 【小题5】

A.Music lowers stress and improves health.
B.Participants who were musicians learned better with light music.
C.Musical training can help raise our IQs and even keep us sharp in old age.
D.Here are amazing scientifically proven benefits of being attracted by music.
E.Recent research shows that listening to music improves our happiness.
F.Softening the lighting and music can lead people to eat fewer calories and enjoy their meals better.
G.To help your children achieve excellence in their studies, encourage them to sing or learn to play an instrument.