Different forests in the western United States have unique combinations of trees and birds. One type has broad-leaved trees like ash and cottonwood, along with kingbirds. Anoher type has evergreen trees like pine and white spruce, along with juncos. Ecologists in the early twentieth century once claimed these ecological communities were precisely balanced systems, where every species had a specific role to play in a complex machine. They believed that removing or adding any plant, bird, or insect, could disrupt this balance and harm the habitat. One of these pioneer ecologists was Frederick Clements, who believed that in a specific climate area, ecological communities gradually moved toward the most balanced and integrated group of species in that region.
Clements was challenged by another pioneer ecologist, Henry Gleason, who took the opposite view. Gleason viewed the community as largely a group of species with similar tolerances to the stresses given by climate and other factors typical of the region. Gleason thought chance played a big role in where species lived. His concept suggests that nature is not highly integrated. Each species is responding individually to its surroundings. Gleason thought things could change in different ways, depending upon local conditions.
Who was right? It now appears that Gleason was more accurate than Clements. The ecological community is mostly a random collection of species with similar responses to a particular climate. Ash trees are found in association with cottonwood trees because both can survive well on floodplains and the competition between them is not so strong that only one can survive.
This is not to say that precise harmonies are not present within communities. Most flowering plants rely on pollinators (传粉者). But if we see a precise balance of nature, it is largely a product of our perception, due to the false belief that nature, especially a complex system like a forest, seems so unchanging from one day to the next.
1. Early 20th century ecologists commonly claimed that___________.A.each species plays a specific role in the community |
B.new species need to be added as communities develop |
C.maintaining precise balance in community is challenging |
D.it is important to protect communities by removing certain species |
A.How individualistic the species is. | B.Their ability to tolerate the stresses there. |
C.The number of similar species present. | D.Their ways to integrate with other species. |
A.To show greater species variety in floodplains. |
B.To provide evidence to support Clements’ theory. |
C.To give an example of species that prefer to live on floodplains. |
D.To support the current view on how ecological communities develop. |
A.culture | B.environment | C.understanding | D.education |
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【推荐1】Scary movies are something you either really love or avoid at all costs. Generally, people should be running away from things that bring fear.
Some people react differently to things that are scary. A study found that people who like scary movies tend to enjoy really strong feelings like fear. When you’re scared, your brain’s immediate response is to fight or flight.
Watching a scary movie is an ideal way to get closer to others. A study found that fear-arousing situations, like watching a scary movie, can increase the attraction between two people. Aside from increasing attraction, it can even bring you closer together. Some even think that scary movies touch a deeper part of our collective consciousness as humans. “It draws us closer when we have a shared experience of being terrified of the dark, or ghosts, or killers,” Brownlowe says.
A.It changes our attitudes to risk. |
B.It’s a great way to make new friends. |
C.People feel more connected to others. |
D.It pushes people into choosing simple tasks. |
E.When this happens, your entire body can react. |
F.But scary movies have a way of drawing people in. |
G.Some anxious people may find scary movies comforting. |
【推荐2】Why Boundaries at Work Are Essential
What is a boundary, you ask? A boundary is a limit defining you in relation to someone or something.
Letting co-workers know you are not comfortable shaking their hands or hugging them at a holiday party, especially with Covid at this time, is another example of setting a physical boundary. It is often easier to understand a physical boundary. Emotional or mental boundaries may be subtler (更微妙的).
Emotional boundaries are related to our feelings and how something or someone’s behavior affects us. For example, if a boss treats you disrespectfully by yelling at you or a colleague frequently interrupts you in meetings, you are likely to feel hurt, embarrassed, and perhaps angry. Understandably, by having a courageous conversation with both your boss and co-worker about their behavior, the impact it has on you, and your expectations regarding future behavior, you are setting healthy emotional boundaries for yourself at work.
Sometimes we set a boundary that is a combination of both a physical and emotional one.
Mental boundaries are related to our beliefs, values, cultural norms, ethics (道德), and standards. For example, you value a workplace culture that treats employees and clients with respect and dignity and acts ethically. After six months, you realize that company leaders are repeatedly behaving in ways not consistent with this.
A.Why are boundaries important? |
B.However, they are equally, if not more, important. |
C.Therefore, we need to tell the difference between them. |
D.Setting a boundary in the above example may be quite helpful. |
E.Boundaries can be physical, mental, emotional, tangible, or intangible. |
F.Your values and ethical standards don’t match with your company’s, which likely will lead to internal conflict. |
G.Such boundaries often involve being asked to do more than we feel capable of for an extended period of time. |
【推荐3】The State of California is depending on its forests to help cut down planet-warming CO2. But that climate-change strategy may be risky, as new research from the University of California, Irvine(UCI)reports that trees in California’s mountains and open spaces are dying from wildfires and other pressures — and fewer new trees are filling the blank.
“The forests are not keeping up with these large fires,” said study co-author James Randerson, the Ralph J. and Carol M. Cicerone Professor of Earth system science at UCI. Across the whole state, tree cover area has dropped 6.7% since 1985. “These are big changes in less than forty years,” he said. It’s the first time that researchers have been able to measure tree population fall in California, and find out the reasons (wildfires and woodcutting).
For the study, the UCI-led team used satellite data from the USGS and NASA’s Landsat mission to study plant changes between 1985 and 2021. They found that one of the most obvious falls in tree cover was in southern California, where 14% of the tree population in local mountain had disappeared, maybe everlastingly.
“The ability of forests to recover(恢复)from fire appears to be dwindling in the south,” said Jonathan Wang, a researcher in Randerson’s research group, who led the study coming out in AGU Advances. “At the same time, the state’s coverage of bushes and grasses is rising, which could mean more everlasting ecosystem shifts(生态系统转化).”
“The speed and scale of fall in tree cover is different across the state. Tree cover in the Sierra Nevada, for example, stayed relatively unchanged until around 2010, then began dropping suddenly. Fortunately, in the north, there’s plenty of recovery after fire,” said Wang, perhaps because of the area’s higher rainfall and cooler temperatures. “This threat(威胁) to California’s climate solutions isn’t going away anytime soon,” Wang said. “We might be entering a new age of bigger fire and vulnerable(易受损的) forests.”
1. What mainly helped California cut down CO2?A.Energy saving. | B.Rich forests. |
C.Less vehicles. | D.Fine weather. |
A.Poor soil. |
B.Continual floods. |
C.High demand for farmland and food. |
D.Large wildfires and people’s cutting trees. |
A.California’s trees will die out in the future. |
B.California’s environment will face a big challenge. |
C.Wildfires seriously threaten California’s tree cover. |
D.The reason for California wildfires has been found out. |
【推荐1】It’s time to go back to high school. Students are excited about the new beginning. But for many kids, the first day is more about friends than classes, and maybe with good reason. On that day, the teacher takes attendance(考勤), hands out books, and describes the teaching plan. If a student hears the same things in seven classes, you can’t blame(责备) them for thinking it’s going to be another long year. When the high schoolers’ parents ask what they did in school, it’s pretty likely that the answer will be “Nothing.”
It doesn’t have to be this way. Kids always want exciting changes, and you can give them a taste of how appealing your course will be. One English teacher asks students to write 77 words about what they want to get out of her class. Then she reads their responses out aloud. She keeps the responses until the last day of the school year. Finally she hands them back to students so that they can see if they achieved what they wanted. After encouraging kids with a year-long game, she begins the English course.
On the first day of science, a teacher gives students 30 minutes to build something to improve people’s lives. A history teacher organizes a debate on whether Swiss cheese is better than cheddar. In math class, another teacher puts students in groups of three, and gives them six minutes to come up with as many answers as possible to the question, “What is math good for?”
The new class activities are part of our school wide movement to improve the first day of classes. Many teachers choose to use creative ways to encourage kids from day one. And all students seem to enjoy the changes. Quite a few parents told me that their kids said, “I think English (or math or biology or Spanish) is going to be great!”
1. Which best describes the class on the first day of school in Paragraph 1?A.Too boring. | B.A bit strange. |
C.Really wonderful. | D.Quite challenging. |
A.Confusing. | B.Ordinary. | C.Attractive. | D.Unfamiliar. |
A.If their writing skills have improved. |
B.If their expectations have been realized. |
C.If they can understand the 77 words. |
D.If the teacher likes their responses |
A.All try to organize different debates. |
B.All ask students to work in groups. |
C.All hold discussions on teaching plans. |
D.All choose to do something exciting. |
But the problems of the next generation or two can more readily be imagined. Scientists have already pointed out that unless something is done either to restrict the world’s rapid growth in population or to discover and develop new sources of food (or both), millions of people will be dying of starvation or at the best suffering from underfeeding before this century is out. But nobody has yet worked out any plan for housing these growing populations. Admittedly the worst situations will occur in the hottest parts of the world, where housing can be light structure or in backward areas where standards are traditionally low. But even the minimum shelter requires materials of some kind and in the teeming, bulging towns the low-standard “housing” of flattened petrol cans and dirty canvas is far more wasteful of ground space than can be tolerated.
Since the war, Hong Kong has suffered the kind of crisis which is likely to arise in many other places during the next generation. Literally millions of refugees arrived to swell the already growing population and emergency steps had to be taken rapidly to prevent squalor(肮脏)and disease and the spread crime. The city is tackling the situation energetically and enormous blocks of tenements(贫民住宅)are rising at an astonishing aped. But Hong Kong is only one small part of what will certainly become a vast problem and not merely a housing problem, because when population grows at this rate there are accompanying problems of education, transport, hospital services, drainage, water supply and so on. Not every area may give the same resources as Hong Kong to draw upon and the search for quicker and cheaper methods of construction must never stop.
1. The writer is sure that in the distant future ___.
A.bricks and mortar will be replaced by some other building material. |
B.a new building material will have been invented. |
C.bricks and mortar will not be used by people who want their house to be fashionable. |
D.a new way of using bricks and mortar will have been discovered. |
A.is difficult to foresee. |
B.will be how to provide enough houses in the hottest parts of the world. |
C.will be how to feed the ever growing population. |
D.is the question of finding enough ground space. |
A.the population growth will be the greatest. |
B.standards of building are low. |
C.only minimum shelter will be possible. |
D.there is not enough ground space. |
A.Hong Kong has faced a serious crisis caused by millions of refugees. |
B.Hong Kong has successfully dealt with the emergency caused by millions of refugees. |
C.Many parts of the world may have to face the kind of problems encountered by Hong Kong and may find it much harder to deal with them. |
D.Hong Kong’s crisis was not only a matter of housing but included a number of other problems of population growth. |
【推荐3】The Voynich manuscript (手稿) is a 234-page book filled with writing in a strange language now called Voynichese. It also features many strange drawings of unknown plants, people and charts. Based on the images alone, it seems to have something to do with medicine.
The language in the manuscript appears nowhere else and has become one of the greatest linguistic riddles of our day, Since its discovery, it has attracted researchers, been called a hoax (骗局), and been the subject of a huge number of articles.
By carbon dating the manuscript, researchers are pretty confident that it was constructed in the early 1400s. And through the magic of linguistic analysis, most people agree that the manuscript is not a hoax. Or, if it is, it’s a very, very complex hoax.
A paper published in 2016 by computer scientist Greg Kondrak and his student Bradley Hauer gained a lot of attention. Their theory was based on the idea that Voynichese was made with a substitution cipher (替代密码). That means it was written in a real language, and then each of the letters in that language was replaced by a specific Voynichese letter.
This is where the computing power comes in. By having a computer compare the text of the Voynich manuscript to 380 languages, Kondrak and Hauer ran the substitution cipher through as many languages as possible and determined if the text would make sense. In the end, they figured out that the original language was Hebrew, and they even translated some of the text. There are a few problems with their results, though: they compared the manuscript to modern Hebrew, not 15th-century Hebrew; they had to make “spelling corrections” for it to make sense; and, possibly most egregious (过分的) of all, they got their results using a translating app.
Despite all the innovations in code-breaking over the last century, the Voynich manuscript still rejects our advances. If Voynichese is indeed ever solved, artificial intelligence could very likely play a role.
1. What can be an agreed point about the Voynich manuscript?A.It’s a medical book. | B.It has magic power. |
C.It was made in the 1400s. | D.It tells the story of a complex hoax. |
A.Voynichese was an endangered language. | B.Voynichese will be replaced soon. |
C.Voynichese was made by somebody. | D.Voynichese will attract more attention. |
A.Its samples were insufficient. | B.It failed to get the text to make sense. |
C.It didn’t determine the original language. | D.Its conclusion was not convincing enough. |
A.Doubt. | B.Expectation. | C.Determination. | D.Concern. |