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However, some experts say that the Atwater system is outdated and inaccurate.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

   A start-up company in California, called Zume, is testing machines that make pizza. The robot takes and shapes dough to create the base of the pizza. It then adds tomato sauce, cheese, meat or other toppings. Next, the robot places the uncooked pizza into a hot oven. A few minutes later, the pizza is ready. The pizza comes out the same each time. Zume says the robots work quickly and do not get sick. The robots do not get paid either.

Julia Collins is the company’s founder and chief executive officer (CEO) . Her business can spend money on better food products because it does not have to pay the robots. Zume is using robots to make pizza.

Charity Suzuki has bought the robot-made pizza. She likes its taste. “It’s delicious. It’s always hot and fresh when it comes. I mean it’s great that they’re making it, but I can’t tell the difference that it’s made by a robot versus a human.”

Other companies say they are developing robots so people can get higher quality food faster. But what about the jobs the robots are taking from humans?

Ken Goldberg is a professor at the University of California in Berkeley. He also directs the school’s automation laboratory. Goldberg says researchers have been working with robots for 50 years. He says that, while there has been progress, the jobs are not going to disappear right away. “I want to reassure (使放心) restaurant workers that the skills that they have are still going to be of value,” Goldberg said.

“We’re going to get rid of boring, repetitive, dangerous jobs and we’re going to free up people to do things that have higher value. There’s going to be amazing new ways of working that don’t exist yet but are going to be created.”

【小题1】Why can Zume devote more money to better food products?

A．It earns a lot by selling pizza.	B．It wants to create more robots.
C．It can save a lot by using robots.	D．It hopes to attract more customers.

【小题2】What can we know about the robot-made pizza according to Suzuki?

A．It really agrees with her.	B．It is hot and fresh all the time.
C．It is tastier than the man-made.	D．It is delicious and free of charge.

【小题3】What’s the benefit of robots’ making pizza?

A．They work efficiently.	B．They help sick people.
C．They need few payments.	D．They produce more food.

【小题4】What does Goldberg think of the jobs of restaurant workers?

A．Interesting.	B．Boring.
C．Dangerous.	D．Necessary.

   According to a recent report, about 15% of the people in the UK are members of gyms. But are they more likely to be fit?

A study found that gym members were 14 times more active than people who didn’t belong to any health club. Gym members did six hours more exercise a week, and this activity did make them fitter than non-gym members. They also spent less time sitting down every day than non-gym members. The results were the same for men and women.

The study included 405 people between the ages of 30 and 64, and the main characteristics of those who were gym members were the same as those who were not. ''But gym members did more training than non-gym members, '' said the lead author, Elizabeth Schroeder of the University of Illinois.

While it might seem clear that gym members exercising more are healthier than non-members, Schroeder says this has not been directly shown before. However, the study is only designed to show a tie between gym membership and more exercise. It may be that active people like to join gyms. In the study, people who exercised as much as gym members were also in good health.

You can get the same benefits wherever you exercise. This study shows a gym membership can make you do more exercise, but other research shows that exercising outside has other help. Outdoor activities can make you feel happy about life—especially if you run through a forest.

Outdoor exercise is also more enjoyable than going to the gym. The first five minutes of outdoor exercise is especially helpful in making people feel good. But Schroeder says that a gym may also encourage greater exercise because it can be social and fun.

【小题1】What did the new study find out?

A．Gym members had healthier eating habits.

B．There were fewer women gym members than men.

C．Gym members did at least eight hours of exercise a week.

D．Gym members were more active than non-gym members.

【小题2】In the study, researchers studied ____________________.

A．some sports lovers

B．405 gym members

C．people from different age groups

D．30 gym members and 64 non-gym members

【小题3】Which of the following will Elizabeth Schroeder agree with?

A．Women should do more gym exercise.

B．We should be careful with outdoor training.

C．Outdoor exercise is better than gym exercise.

D．It is easier to keep exercising if you go to the gym.

   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.

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Global warming could make humans shorter, warn scientists who are said 【小题1】（find）evidence that it caused the world’s first horses to shrink nearly 50 million years ago.

In fact, a team from the universities of Florida and Nebraska says it has found a link between the earth 【小题2】（heat）up and the size of mammals — horses. The scientists used fossils to follow the evolution（进化）of horses from their earliest 【小题3】（appear）56 million years ago.

“As temperatures went up, 【小题4】（they）size went down, and vice versa; at one point they were as small as a house cat,” said Dr. Jonathan Bloch, curator of the Florida Museum of Natural History. The scientists say that the current warming could have the same effect 【小题5】 mammals — and could even make humans 【小题6】（small）.

Horses 【小题7】（start）out small, about the size of a small dog like a miniature schnauzer.【小题8】 is surprising is that after they first appeared, they then became even smaller and then dramatically increased in size, and that 【小题9】（exact）agrees with the global warming event. “It had been known that mammals were small when it was warm,【小题10】 we hadn’t understood that the temperature really was driving the evolution of body size,” Dr. Bloch said in the Science journal.