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However, some experts say that the Atwater system is outdated and inaccurate.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

   Just like humans, birds rely on sound to communicate, too. Often, birds recognize their mates or young by sound rather than sight. Hungry young birds use begging calls to let their mothers know it is feeding time, and warning calls are other sounds given out frequently by the adults. In addition to all these regular calls, some male birds develop beautiful songs intended（打算）to attract the females.

A new study carried out by an American university shows that songbirds practice their songs even in their sleep. The research team discovered that the electrical brain activity of the birds that were asleep was similar to the brain activity produced when the birds were awake and singing. Clearly the bird stores a song after hearing it, then practices it later in its sleep. Scientists now believe the birds dream of songs to help them master the fine art of singing and that sleep plays a key role in the learning process！

It is commonly known that many songbirds learn to sing by listening to adult birds of the same species. If taught the song of an adult of another bird species, the chick grows up singing the new song and passes on the foreign song to its chicks. For instance, researchers carried out an experiment in which a male bullfinch（红腹灰雀）was raised by a female canary（金丝雀）. The bullfinch soon learned the canary's songs and when it was later mated to a female bullfinch, Mr. Bullfinch taught his children the canary's songs.

Early last year, a British survey of London's songbirds showed that the city's birds are losing their melodies. Birds could hardly hear one another over the traffic noise；as a result they had difficulty in learning songs and communicating with potential mates. And instead of copying the sweet notes of the adults, chicks were copying sounds, which they heard most often—namely car horns（喇叭）and mobile phones！

【小题1】What can we learn according to Paragraph 2？

A．Sleep helps songbirds master new songs.

B．Songbirds can even hear songs in their dreams.

C．The study was carried out by Australian scientists.

D．The brain activity of songbirds would stop in their sleep.

【小题2】Why does Mr. Bullfinch teach his children the canary's songs？

A．Because he wants to help them learn a foreign language.

B．Because he can't sing bulfinches' songs.

C．Because he wants to make them get along well with other birds.

D．Because the canary's songs are more attractive.

【小题3】What's the problem of the city's birds according to the passage？

A．They have lost their voices.

B．They are losing their habitats.

C．They are bothered by the city's noises.

D．They tend to refuse to learn songs from adults.

【小题4】What conclusion can we draw from the passage？

A．The city's birds can learn more songs.

B．All birds learn foreign songs during their life.

C．It may be difficult for the city's birds to find their mates.

D．Young birds can tell the difference between songs and noises.

   A newly-published study has shown that loneliness can spread from one person to another，like a disease. Researchers used information from the Framingham Heart Study，which began in 1948. The Framingham Heart Study gathers information about physical and mental health，personal behavior and diet. At first，the study involved（使参加）about 5,000 people in the American state of Massachusetts. Now more than 12,000 individuals（个人）are taking part.

Information from the Framingham Heart Study showed earlier that happiness can spread from person to person. So can behavior like littering and the ability to stop smoking.

Psychologist John Cacioppo，at the University of Chicago，led the recent study. He and other researchers tried to show how often people felt lonely. They found that the feeling of loneliness spread through social groups.

Having a social connection with a lonely person increased the chances that another individual would feel lonely. In fact，a friend of a lonely person was 52% more likely to develop feelings of loneliness. A friend of that person was 25%more likely. The researchers said this shows that a person could indirectly be affected by someone’s loneliness.

The effect was the strongest among friends. Neighbors were the second most affected group. The effect was weaker on husbands and wives，and brothers and sisters. The researchers also found that loneliness spread more easily among women than men.

The New York Times newspaper reported that，on average，people experience feelings of loneliness about 48 days a year. It also found that every additional（额外的）friend can decrease loneliness by about five percent，or two and a half fewer lonely days.

Loneliness has been linked to health problems like depression（抑郁症）and sleeping difficulties. The researchers believe that knowing the causes of loneliness could help reduce it.

The study suggested that people can take steps to stop the spread of loneliness. They can do this by helping individuals they know who may be experiencing loneliness. The result can be helpful to the whole social group.

【小题1】As for the Framingham Heart Study we can learn that __________.

A．it was only conducted in 1948	B．it involves more than 12, 000 people
C．it was founded by John Cacioppo	D．it showed that any behavior could spread

【小题2】From the passage, we can learn that __________.

A．the behavior of littering doesn’t spread

B．a lonely person won’t have friends

C．everyone may be affected by others’ loneliness

D．lonely people don’t know the causes of their loneliness

【小题3】Which statement about the spread of loneliness is TRUE?

A．The spreading effect is the second strongest among friends.

B．No spreading effect is found on husbands and wives.

C．Women are more likely to be affected than men.

D．Brothers are more easily to be affected than neighbors.

【小题4】What is the main idea of the passage？

A．Action should be taken to help lonely people.	B．People feel lonely for many reasons.
C．Ways to fight against loneliness.	D．Lonely people can affect others.

Thinking is something you choose to do as a fish chooses to live in water. To be human is to think. But thinking may come naturally without your knowing how you do it. Thinking about thinking is the key to critical（批判性的）thinking. When you think critically, you take control of your thinking processes（过程）. Otherwise, you might be controlled by the ideas of others. Indeed, critical thinking is at the heart of education.
The word "critical" here has a special meaning. It does not mean taking one view against another view, as when someone criticizes another person for doing something wrong. The nature of critical thinking is thinking beyond the easily seen—beyond the pictures on TV, the untrue reports in the newspapers, and the faulty reasoning (错误的推理).
Critical thinking is an attitude as much as an activity. If you are curious about life and desire to dig deeper into it, you are a critical thinker; if you find pleasure in deep thinking about different ideas, characters, and facts, you are a critical thinker.
Activities of the mind and higher-order reasoning are processes of deep and careful consideration. They take time, and do not go hand in hand with the fast speed in today's world, fast foods, instant coffee, and self-developing film. If you are among the people who believe that speed is a measure of intelligence, you may learn something new from a story about Albert Einstein. The first time Banish Hoffman, a scientist, was to discuss his work with Albert Einstein, Hoffman was too nervous to speak. But Einstein immediately put Hoffman at ease by saying, "Please go slowly, I don't understand things quickly."
【小题1】Critical thinking is important to us because if we do not think critically,__________.

A．it will be hard for us to think naturally and fast

B．we will follow the ideas of others naturally

C．we might be controlled by other people's ideas

D．we might be fooled by other people's ideas

【小题2】If you are a critical thinker, you will________.

A．criticize other people for their mistakes	B．trust the reports in the newspapers
C．take one view against another view	D．think deeply about different ideas

【小题3】In the last paragraph, "something new" suggests that________.

A．the smarter you are, the faster you do things

B．intelligence is not decided by speed

C．speed can improve intelligence

D．the faster you do things, the smarter you become

【小题4】What would be the best title for the passage?

A．Understanding Critical Thinking	B．Thinking and Critical Thinking
C．Thinking Natural and Human	D．Thinking Fast Means Intelligence

   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.