If the eyes are the romantic’s window into the soul, then the teeth are an anthropologist’s door to the stomach.
In a study published recently in the journal Science, Peter Ungar of the University of Arkansas and his partner, Matt Sponheimer of the University of Colorado, US, examined the teeth of ancient human beings to find out what they were really eating.
They already knew that different foods cause different marks on teeth. Some cause scratches, while others cause pits(坑). The carbon left on teeth by different foods is also different. Tropical grasses, for example, leave one kind of carbon, but trees and bushes leave another kind because they photosynthesize(进行光合作用)differently.
Traditionally, scientists had looked at the size and shape of teeth and skulls to figure out what early humans ate. Big flat teeth were taken to be signs that they ate nuts and seeds, while hard and sharp teeth seemed good for cutting meat and leaves. But this was proved wrong.
The best example was the Paranthropus(傍人属类人猿), one of our close cousins, some of whom lived in eastern Africa. Scientists used to believe that they ate nuts, fruits and seeds because they had big crests(突起)on their skulls, suggesting that they had large chewing muscles and big teeth. If this had been true, their teeth should have been covered with pits like the surface of the moon. They would also have had a particular type of carbon on their teeth that typically comes from tree products, such as nuts and seeds.
However, when the two scientists studied the Paranthropus, it turned out to have none of these characteristics. The teeth had a different kind of carbon, and were covered with scratches, not pits. This suggested they probably ate grass, not nuts and seeds. It was the exact opposite of what people had expected to find.
Carbon “footprints” give us a completely new and different understanding of what different species ate and the different environments they lived in, which also provide a groundbreaking perspective on the diets and habitats of various species. This method has reshaped our understanding of ancient human diets, challenging previous assumptions based on tooth and skull morphology.
1. Which of the following best explains the underlined sentence?| A．Anthropologists can know the structure of human stomachs by studying their teeth. |
| B．Anthropologists can find out the diet of early humans by studying their teeth. |
| C．Anthropologists can learn whether humans were healthy by looking at their teeth. |
| D．Anthropologists can get the most useful information about humans from their teeth. |
| A．Pits on teeth are caused by eating grass or leaves. |
| B．Scratches on teeth are caused by eating nuts or seeds. |
| C．Different foods leave different marks and carbon on teeth. |
| D．Early humans with hard and sharp teeth at e meat and leaves. |
| A．To show they had different eating habits from other humans. |
| B．To prove living environment makes a difference to skull structure. |
| C．To demonstrate they were one of our close cousins living in eastern Africa. |
| D．To reveal the size and shape of teeth don’t show accurately what early humans ate. |
| A．Cause and effect. |
| B．Problem and solution. |
| C．Comparison and contrast. |
| D．Listing and classification. |
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【推荐1】I love my gas stove. There’s nothing quite like cooking over that beautiful blue flame. But in recent years environmentalists have been warning that gas stoves are bad for the climate and not so great for our health, either. Two new studies have heightened health worries about harmful gases in our kitchens. Is the evidence sufficient to change our cooking habits? For me, the answer is yes.
Broadly speaking, there are two categories of concerning emissions related to gas stoves. First, there is the unburned natural gas, which is more than 90 percent methane. More than three quarters of methane that escapes from a stove leaks into kitchens when it is not in use, most likely through improper pipe fittings. Methane is not poisonous, but it is a powerful greenhouse gas. With 40 million gas stoves across our country, it is estimated that the heat-trapping potential of the methane they send out annually can roughly be compared to the carbon dioxide released by half a million gas-powered cars.
Second, there are the pollutants created by combustion when a burner is on, most notably nitrogen oxides, which can cause discomfort and pain in the lungs. In a matter of minutes, families who do not use their exhaust hoods and who have small, poorly ventilated kitchens can go over the Environmental Protection Agency’s outdoor exposure limit for nitrogen dioxide. Even short exposures to much nitrogen dioxide can worsen symptoms in people with respiratory conditions. And there is enough evidence that long-term exposure raises the risk of developing asthma.
What is the average home cook to make of all this? They might take a cue from Michanowicz, who bought a plug-in countertop induction stove and does much of his cooking on that $100 item. Jackson, for his part, is putting his money where his research is: “I’m replacing a perfectly good gas stove” with an induction stove. Several U.S. cities are curtailing the use of natural gas in new construction.
As for me, I’m making some changes. I’ve switched to an electric kettle for boiling water, and despite its annoying noise, I now use the exhaust hood over my stove. And weather permitting, I’ll open a window.
1. What does the author want to show by mentioning two new studies?| A．She might well get out of her cooking habits. |
| B．Health worries are proved by the two studies. |
| C．It’s not for her to judge despite sufficient evidence. |
| D．She will continue to cook with her beloved gas stove. |
| A．Methane can test the destructive power of greenhouse gas. |
| B．Most methane will leak into kitchens when a stove is not in use. |
| C．The leakage of methane into kitchens is possibly through imperfect pipe fittings. |
| D．The heat-trapping potential of methane is equal to the carbon dioxide released by cars. |
| A．Guaranteeing. | B．Limiting. | C．Increasing. | D．Embracing. |
A． | B． | C． | D． |
Sound is very important in our daily lives.Most of us get information and know what’s happening around us by the sounds we hear.We talk with other people and listen to radio and television broadcasts for music,news,and enjoyment.
Sound can be useful and pleasing or it can be unpleasant,and damaging to our ears.Unwanted,harmful sounds are called noise pollution.
The movements of people,animals,machines,and other things cause pressure waves in the air.If these pressure waves are within a certain range(范围)of frequencies(频率),our ears believe that it is sound.Sound waves are like the waves in a lake when you throw a stone.The bigger the stone,the bigger the waves.And that’s how sound works.Big sounds cause larger waves.
Scientists measure these sound waves in decibels.To be heard by humans,a sound wave must measure at least ten decibels.When these waves reach a high number of decibels,our ears start to hurt and damage can occur.If you’ve been around loud noises for several hours,you may have experienced damage.It’s important to know the danger signal:ringing in your ears.
Keep your ears safe-be careful what you hear!
1. What is noise pollution?
2. What may damage our ears?
3. What is the passage mainly about?
【推荐3】If you exhibit positive characteristics, such as honesty and helpfulness, the chances are that you will be thought as a good-looking person, for a new study has found that the perception (认知) of physical attractiveness is influenced by a person’s personality.
The study, which was led by Gary W. Lewandowski, has found that people who exhibit negative characteristics, such as unfairness and rudeness, appear to be less physically attractive to observers. In the study, the participants viewed photographs of opposite-sex individuals and rated them for attractiveness before and after being provided with information about their personalities.
After personality information was received, participants also rated the probability of each individual’s becoming a friend and a dating partner. Information on personality was found to significantly change the probability, showing that cognitive (认知的) processes modify (修改) judgments of attractiveness.
“Thinking a person as having a desirable personality makes the person more suitable in general as a close relationship partner of any kind,” said Lewandowski.
The findings show that a positive personality leads to greater expectation of becoming friends, which leads to greater expectation of becoming romantic partners and, finally, to being viewed as more physically attractive. The findings remained consistent regardless of how “attractive” the individual was formerly thought to be or of the participants’ current relationship status.
“This research provides a positive outcome by reminding people that personality goes a long way toward determining your attractiveness; it can even change people’s impressions of how good-looking you are,” said Lewandowski.
1. In the study the participants were required to ______.| A．try to make friends with each other |
| B．try to prove positive characters make people more attractive |
| C．exhibit negative characters such as unfairness and rudeness |
| D．rate one’s attractiveness by photos before and after knowing her or his personality |
a. find a person with a positive personality
b. view the person more physically attractive
c. want to make friends with the person
d. want to be his/her romantic partner
| A．a→c→d→b | B．d→c→b→a | C．c→b→a→d | D．a→d→c→b |
| A．The research reminds people to pay more attention to the personality. |
| B．Personality can change people’s impressions of one’s appearance. |
| C．The judgment of one’s attractiveness always stays unchanged. |
| D．Positive personality may lead to more friends. |
| A．subjective | B．objective | C．skeptical | D．negative |
| A．People with positive characteristics. | B．Good-looking people. |
| C．People with negative characteristics. | D．General people. |
【推荐1】Drugs come in different forms. However，can you imagine that drugs come in chicken eggs？A team of scientists from England prove that it can come true. They have developed special chickens that lay eggs with drugs inside. These special drugs can help treat some kinds of diseases. Until now，they have made two kinds of drugs. One drug can treat skin cancer and the other can treat a nerve disease （神经性疾病）.
Certain drugs are produced by the special chickens inside their egg whites. These drugs are made of proteins（蛋白质） which can be found in animals' skin，hair，milk and meat. The scientists also use DNA technology to make sure that the drugs are only inside the egg whites. In this way，the chickens can stay healthy.
Besides egg whites，drugs made of proteins come in milk of cows and sheep. Compared with cows and sheep，the special chickens have ascendancy over them. First，they are cheaper to raise. Second，they need less room and grow faster.
These special chicken can pass on their drug﹣producing ability to their children. So far，five generations （代） of the special chickens have appeared. But scientists may need more time to make the drugs perfect. It's said that scientists will realize their dream in five to ten years.
1. The underlined word "ascendancy" in the passage means" "in Chinese.| A．情况 | B．优势 | C．劣势 |
| A．pills that can treat all cancers | B．just the scientists' imagination | C．made of proteins |
| A．need less room and grow faster |
| B．were developed by scientists from France |
| C．produce certain drugs outside the eggs |
| A．The scientists never use DNA technology to keep the special chickens healthy. |
| B．It may take scientists more time to make the drugs perfect. |
| C．Until now，scientists have made three kinds of drugs. |
| A．It's mainly about a serious disease. |
| B．It's mainly about a natural ability of the special chickens. |
| C．It's mainly about the special drugs. |
【推荐2】Many people who want to lose weight often choose to go on a diet. But is this really the best method? With celebrities speaking about new diets that have helped them slim down in advertisements, more and more people are turning to dieting. Shops have noticed this trend and are stocking their shelves with diet products such as diet milkshakes, snack bars and even diet pills. But, such products and the diets they are associated with are often found to be extremely unhealthy.
Most of these popular diets work by cutting out a certain nutrient from your food intake. For example, some diets work by cutting out carbohydrates. This means the body must use its fat reserves for energy. This might help you lose weight. However, by cutting a particular food group out of your diet, you are starving your body of a nutrient that it needs, which could leave you feeling weak, tired or even bad-tempered. Furthermore, these diets are often unsuccessful in the long run.
Generally, following a strict diet or cutting out a particular food group is not an effective way to lose weight. One of the most effective ways is to cut down on calories. The recommended calorie intake for an adult male is 2, 500. If a man consumes more than 2, 500 calories each day, then he is likely to gain weight. However, if he consumes less, then he is likely to lose weight, especially if he exercises.
So, instead of spending money on trendy diet pills or special weight loss foods, try to eat healthy balanced meals containing foods from all food groups. Proteins, carbohydrates, fats, vitamins and minerals all play an important role in staying healthy, which is why they all should be included in your meals. Of course, some foods can be eaten in moderation as an occasional snack. For example, a bar of chocolate every once in a while won’t cause you any problems. So, next time a friend of yours tells you that they are going on a diet, let them know that eating a healthy balanced diet is a much better choice.
1. What does the author say about popular diets in paragraph 1?| A．They are often promoted by celebrities. | B．They are welcomed by celebrities. |
| C．They are useful for losing weight. | D．They are replacing people’s everyday meals. |
| A．Doubtful. | B．Unfavorable. | C．Curious. | D．Unconcerned. |
| A．By having diet pills. | B．By following a strict diet. |
| C．By taking regular exercise. | D．By reducing calorie intake. |
| A．Diet products should be limited. |
| B．Snacking is a big no-no for health. |
| C．Keeping a diet with various nutrients is ideal. |
| D．Going on a diet should be approached with care. |
【推荐3】Open Hearts to Life
We often close ourselves off when unlucky events happen in our lives. We try to reduce the hurt and pain by pretending it doesn’t exist.
Breathe into pain.
Whenever a painful situation arises in your life, try to embrace it instead of running away.
I know we’ve all felt decisions or actions that we had to take simply due to our “gut” impulses(冲动): when asked, we can’t explain the reasons behind doing so — just a deep knowing that it had to get done. To start this process, take few deep breaths and then ask, “Heart, what decision should I make here? What action feels the most right?” See what comes up, then take action and evaluate the outcome.
Spend time alone.
For most of our lives we’re surrounded by people: our friends, colleagues, family members, and strangers. How often do we really spend time alone? When you spend time in solitude, you’re free from the influences of other people, and can truly open yourself and explore whatever you’d like. See where your thoughts take you.
Get outside of yourself.
| A．Embrace the uncomfortable. |
| B．Ask your heart what it wants. |
| C．In the end, though, we can’t hide from ourselves. |
| D．We should take a step back and re-evaluate our behavior. |
| E．When the sadness strikes, take a deep breath and lean into it. |
| F．The golden ticket here is to not let yourself become distracted; just see what it’s like to be alone. |
| G．This may seem a little contradictory to the last tip, but in reality, they actually work hand-in-hand. |
