1 . 阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

A comprehensive study of 4,500 children conducted by the National Institutes of Health in 2018 shows that children who spent more than seven hours a day staring at screens showed evidence of premature thinning of their brain's cortex一the outer layer that processes sensory information. "We don't know if it     1     (cause) by the screen time. We don't know yet if it's a bad thing. It won't be until we follow them over time     2     we will see if there are outcomes that are associated with the differences that we're seeing in this single snapshot, Dr. Gaya Dowling. ^uWhat we can say is that this is     3    the brains look like of kids who spend a lot of time on screens. And it's not just one pattern."

The problem isn't just screens     4    , but also the way screens tempt kids (and adults) away from something far more important: physical activity. More than 23 percent of adults and 80 percent of adolescents don't get enough physical activity, and according to a 2019 report from the World Health Organization (WHO) , these patterns of activity and rest arise     5    habits we develop early in life. ^uWhat we really need to do is     6     (bring) back play for children," says Dr. Juana Willumsen, a WHO specialist in childhood obesity and physical activity, in a statement about new WHO guidelines issued in April 2019. “ This is about making the shift from sedentary time to playtime, while       7     (protect) sleep. Of course, children aren't completely to blame for their screen addiction.

Sometimes, the parents     8    complain about the role of screens in family life are just as guilty of spending too much time in front of one. A 2016 study       9     (conduct) by Common Sense Media found that parents spend up to nine hours a day in front of screens, mostly not for work-related reasons. While 78 percent of parents said they believed they were good screen time role models, the study found a disconnect between their behavior and their perception of their behavior. Parents need to limit screen time for themselves and especially for their kids一       10     it means playing the bad guy. Our mental and physical health depends on it.

2 . When 17-year-old Quattro Musser hangs out with friends, they don't drink beer or cruise around in cars with their dates. _____, they stick to G-rated activities such as rock- climbing or talking about books.

They are in good company, according to a new study showing that teenagers are increasingly delaying activities that had long been seen as rites of passage into _____. The study, published Tuesday in the journal Child Development, found that the percentage of adolescents in the U. S. who have a driver's license, who have tried alcohol, who date, and who work for pay has plummeted since 1976, with the most precipitous (急剧的) _____ in the past decade. The declines appeared across race, geographic, and socioeconomic lines, and in rural, urban, and suburban areas.

To be sure, more than half of teens still engage in these activities, but the _____ have slimmed considerably. Teens have also reported a steady decline in sexual activity in recent decades, as the portion of high school students who have had sex fell from 54 percent in 1991 to 41 percent in 2015, according to Centers for Disease Control statistics. ^u People say, 'Oh, it's because teenagers are more responsible, or more lazy, or more boring, ' but they're _____ the larger trend," said Jean Twenge, lead author of the study, which drew on seven large time-lag surveys of Americans. Rather, she said, kids may be less _____ in activities such as dating, driving or getting jobs because in today's society, they no longer need to.

According to an evolutionary psychology theory that a person's "life strategy" slows down or speeds up depending on his or her _____, exposure to a "harsh and unpredictable" environment leads to faster development, while a more resource-rich and secure environment has the _____ effect, the study said. In the first _____, "You'd have a lot of kids and be in survival mode, start having kids young, expect your kids will have kids young, and expect that there will be more _____and fewer resources, " said Twenge, a psychology professor at San Diego State University who is the author of "iGen： Why Today's Super- Connected Kids Are Growing Up Less Rebellious, More Tolerant, Less Happy-and Completely Unprepared for Adulthood."

In that model a teenage boy might be thinking more _____ about marriage, and driving a car and working for pay would be important for “ establishing mate value based on procurement of resources," the study said. But America is shifting more toward the _____model, and the change is apparent across the socioeconomic spectrum, Twenge said. ^uEven in families whose parents didn't have a college education. . . families are smaller, and the idea that children need to be carefully   _____ has really sunk in. ‘‘ The _____of ⁴¹ adult activities'' could not be attributed to more homework or extracurricular activities, the study said, noting that teens today spend fewer hours on homework and the same amount of time on extracurriculars as they did in the 1990 s (with the exception of community service, which has risen slightly). Nor could the use of smartphones and the Internet be entirely the _____, the report said, since the decline began before they were widely available. If the delay is to make room for creative exploration and forming better social and emotional connections, it is a good thing, he said.

1.

A．Therefore

B．Rather

C．Moreover

D．Besides

2.

A．childhood

B．neighborhood

C．adolescents

D．adulthood

3.

A．escapes

B．ends

C．decreases

D．changes

4.

A．minorities

B．majorities

C．masses

D．amounts

5.

A．taking

B．avoiding

C．sending

D．missing

6.

A．interested

B．envied

C．relieved

D．realized

7.

A．emotions

B．surroundings

C．customs

D．habits

8.

A．wrong

B．same

C．opposite

D．similar

9.

A．event

B．issue

C．case

D．occasion

10.

A．trouble

B．questions

C．benefits

D．diseases

11.

A．respectively

B．delicately

C．seriously

D．considerably

12.

A．slower

B．better

C．smaller

D．faster

13.

A．emphasized

B．related

C．organized

D．educated

14.

A．implement

B．postponement

C．achievement

D．payment

15.

A．cause

B．impact

C．fact

D．result

3 . _____ you may have, you should gather your courage to face the challenge.

A．However a serious problem	B．What a serious problem
C．However serious a problem	D．What serious a problem

4 . Bitcoin and other so-called cryptocurrencies （加密货币）have been all over the news lately. Apparently, the idea of money that's not tied to a specific bank—or a specific country—is appealing to many. But it's worth remembering that the banking system that we now all live with is just that： A modern invention. Not so long ago, money was almost always created and used locally, and bartering was common. （In fact, it still is common among many online local networks, like the Buy Nothing Project.）.

In the past, money's makeup varied from place to place, depending on what was considered valuable there. So while some of the world's first coins were made from a naturally occurring hybrid of gold and silver called electrum （银金矿），objects other than coins have served as currency, including beads, ivory, livestock, and cowrie shells. In West Africa, bracelets of bronze or copper were used as cash, especially if the transaction was associated with the slave trade there. Throughout the colonial period, tobacco was used to replace coins or paper bills in Virginia, Maryland and North Carolina, even though it was used elsewhere in the colonies and extensively throughout Europe and the U. K.

Today, on an island in the Pacific, a specific type of shell still serves as currency—and some people there are even hoarding（贮存）it, just like Bitcoin moguls, convinced that one day, it will make them wealthy beyond imagination. On Malaita, the most-populated island that's part of the Solomon Islands, shells are accepted at most places in exchange for goods.

"How much tuna（金枪鱼）you can get for your shells depends on their color and shape," Mary Bruno, a shop owner from the small town of Auki, on Malaita, told Vice. "One strip of darker shells might get you about two cans of smaller tuna, but the red ones are worth more. For the red ones, one strip might get enough tuna to feed a big family for a long time."

Just like a mint that creates coins, there's only one place on the island where the shells, which are polished and strung together to form 3-foot-long ropes, are made. The strips of red, white, and black shells all come from Langa Langa Lagoon, where artificial islands were long-ago built by locals to escape from the island-dwelling cannibals. Once marooned（困住）out on their islands, locals needed a currency to use among themselves, and so the shell currency was born.

Using shells for money was common throughout the Pacific islands as late as the early 1900s, but Malaita is unique in that they are still used today. And just like cryptocurrencies, there are those who think the islanders are smart to invest in this type of money, which is reported to have risen in value over the last three decades. It might seem strange to hoard a bunch of processed, strung-together shells, but what is a pile of dollars? Just a specially printed piece of paper and hemp that we've assigned value to—and probably less durable over time than those shells.

1. According to the passage, which of the following is TRUE?

A．Money was created and was widely used in the world.

B．Tobacco was used as coins or paper bills in American in the past.

C．The ingredients of world’s first coins may be the combination of gold and silver.

D．Using shells for money has been out of date in the world.

2. The word "mint" in paragraph 5 is closest in the meaning to     .

A．a kind of money that can exchange

B．the leaves of a mint plant used fresh or candied

C．a place to produce and polish shells

D．a factory that produces currency

3. What's opinion of the author towards shells for money?

A．Reasonable.	B．Imaginary.
C．Convenient.	D．Inventive.

4. Which of the following might be the best title of the passage?

A．The History of Bitcoin

B．Shells Still Money

C．The Currency Is of Great Use

D．Some Shells

5 . Understand the Economic Concept of a Budget Line

The term “budget line" has several related meanings, including a couple that are self-evident and a third that is not.

The Budget Line as an Informal Consumer Understanding

The budget line is an elementary concept that most consumers understand intuitively without a need for graphs and equations—it's the household budget, for example.

Taken informally, the budget line describes the boundary of affordability for a given budget and specific goods.

Given a limited amount of money, a consumer can only spend that same amount buying goods. If the consumer has X amount of money and wants to buy two goods A and B, she can only purchase goods totaling X. If the consumer needs an amount of A costing 0. 75 X, she can then spend only 0. 25 X, the amount remaining, on her purchase of B.

This seems almost too obvious to bother writing or reading about. As it turns out, however, this same concept——one that most consumers make many times each day with reflecting on it—is the basis of the more formal budget line concept in economics, which is explained below.

Lines in a Budget

Before turning to the economics definition of “budget line" , consider another concept: the line-item budget. This is effectively a map of future expenditures, with all the constituent expenditures individually noted and quantified. There's nothing very complicated about this； in this usage, a budget line is one of the lines in the budget, with the service or good to be purchased named and the cost quantified.

The Budget Line as an Economics Concept

One of the interesting ways the study of economics relates to human behavior generally is that a lot of economic theory is the formalization of the kind of simple concept outlined above— a consumer's informal understanding of the amount she has to spend and what that amount will buy.

In the process of formalization, the concept can be expressed as a mathematical equation that can be applied generally.

A Simple Budget Line Graph

To understand this, think of a graph where the vertical lines quantify how many movie tickets you can buy and where the horizontal lines do the same for crime novels. You like going to the movies and reading crime novels and you have $ 150 to spend. In the example below, assume that each movie costs $ 10 and each crime novel costs $ 15. The more formal economics term for these two items is budget set.

If movies cost $ 10 each, then the maximum number of movies you can see with the money available is 15. To note this you make a dot at the number 15 (for total movie tickets) at the extreme left-hand side of the chart. This same dot appears at the extreme left above "0" on the horizontal axis because you have no money left for books—the number of books available in this example is 0.

You can also graph the other extreme—all crime novels and no movies. Since crime novels in the example cost $ 15 and you have $ 150 available, if you spend all the available money crime novels, you can buy 10. So you put a dot on the horizontal axis at the number 10.

You'll place the dot at the bottom of the vertical axis because in this instance you have $ 0 available for movie tickets.

If you now draw a line from the highest, leftmost dot to the lowest, rightmost dot you'll have created a budget line. Any combination of movies and crime novels that falls below the budget line is affordable. Any combination above it is not.

1. Which sentence about the budget line is NOT TRUE?

A．It is a limitation of affordability for a given budget and specific goods.

B．Most costumers will be confused with this concept because of its complex.

C．It is the effectively a map of future expenditures.

D．It can be expressed as a mathematical equation.

2. What is the purpose of the passage?

A．To tell us any concept can be expressed as a mathematical equation.

B．To help us figure out the meaning Budget Line.

C．To tell us we should budget before we buy goods.

D．To give an instruction of drawing a budget Line.

3. Assume that each movie costs $ 10 and each crime novel costs $ 15, you have $ 150.Which is RIGHT according to this passage?

A．The maximum number of movies you can see is 10.

B．The maximum number of crime novels you can buy is 15.

C．You can buy 7 crime novels and see 5 movies.

D．You can buy 7 crime novels and see 4 movies.

4. What is the best title of this passage?

A．Are we really know the economic concept of a budget line?

B．The Budget Line as an Economics Concept

C．The Budget Line as an Informal Consumer Understanding

D．The Complex Concept—Budget Line

6 . For some people,music is no fun at all. About four percent of the population is what scientists call “amusic.” People who are amusic are born without the ability to recognize or reproduce musical notes(音调). Amusic people often cannot tell the difference between two songs. Amusics can only hear the difference between two notes if they are very far apart on the musical scale.

As a result, songs sound like noise to an amusic. Many amusics compare the sound of music to pieces of metal hitting each other. Life can be hard for amusics. Their inability to enjoy music sets them apart from others. It can be difficult for other people to identify with their condition. In fact, most people cannot begin to grasp what it feels like to be amusic. Just going to a restaurant or a shopping mall can be uncomfortable or even painful. That is why many amusics intentionally stay away from places where there is music. However, this can result in withdrawal and social isolation. “I used to hate parties,” says Margaret,a seventy-year-old woman who only recently discovered that she was amusic. By studying people like Margaret, scientists are finally learning how to identify this unusual condition.

Scientists say that the brains of amusics are different from the brains of people who can appreciate music. The difference is complex, and it doesn't involve defective hearing. Amusics can understand other nonmusical sounds well. They also have no problems understanding ordinary speech. Scientists compare amusics to people who just can't see. certain colors.

Many amusics are happy when their condition is finally diagnosed(诊断). For years, Margaret felt embarrassed about her problem with music. Now she knows that she is not alone. There is a name for her condition. That makes it easier for her to explain. “When people invite me to a concert, I just say,” No thanks, I'm amusic,'“says Margaret. “I just wish I had learned to say that when I was seventeen and not seventy.”

1. Which of the following is true of amusic?

A．Listening to music is far from enjoyable for them.

B．They love places where they are likely to hear music.

C．They can easily tell two different songs apart.

D．Their situation is well understood by musicians.

2. According to Paragraph 3, a person with “defective hearing” is probably one who ___________.

A．dislikes listening to speeches

B．can hear anything nonmusical

C．has a hearing problem

D．lacks a complex hearing system

3. In the last paragraph, Margaret expressed her wish that __________.

A．her problem with music had been diagnosed earlier

B．she were seventeen years old rather than seventy

C．her problem could be easily explained

D．she were able to meet other amusics

4. What is the passage mainly concerned with?

A．Amusics' strange behaviours.

B．Some people's inability to enjoy music.

C．Musical talent and brain structure.

D．Identification and treatment of amusics.

7 . Magazine Articles: More Valuable Than You May Think

Parents are often surprised when teachers suggest their children read magazines. Read on to learn about the benefits that reading magazines offers to young readers and how to introduce your children to the medium.

Magazine Benefits

Magazine articles can provide reluctant readers with a lively, breezy writing style that can inspire them to read more.

The articles in magazines are generally short, which allows a child to finish reading a feature article without losing interest due to a short attention span. The writing in magazines also tends to be easy to read, especially if it is a children's publication.

By allowing your child to read magazines at an early age, you are encouraging development of a useful skill.    1    Getting into the habit of reading periodicals as a child will foster the habit of reading news articles that may continue into adulthood.

    2     Magazine articles challenge students to think about issues they may have never considered or cause them to rethink their world view. Information is available in a wide variety of reading levels because magazines are written for every audience imaginable. Many publications cover the same material in different writing styles that might make it easier for your child to comprehend.

Magazine Activities

Reading magazines as a family can be used to introduce each other to the various interests that each family member possesses. When your children are finished with their magazines, encourage them to pass their issue on to a sibling or other family member.

Once each family member has finished reading each magazine, you can use them for art and writing projects. These projects are for family members of all ages:

1. Cut out pictures to help your preschool and kindergarten children learn their alphabet, numbers, and colors.

2.    3     Paste the picture at the top of a page and have them write a story about what is happening or what the picture represents.

3. Clip pictures to create a collage. Many teenagers love using their artistic talents to collage.

    4    The skills that students utilize and strengthen when reading magazines can be applied to higher level reading and other academic subjects. Encouraging your child to read by giving them a magazine subscription could cause them to take the leap from being a reluctant N reader to a voracious page-turner.

A．The format of magazines enables children to be exposed to a wide variety of subjects.

B．Magazines and newspapers provide adults with critical news.

C．Being exposed to magazines and newspapers benefits you a lot.

D．Keep interesting magazine pictures to give children story ideas.

E．Magazines are valuable assets for many people, but in particular to children.

F．Magazines and newspapers are expensive now but out of style.

8 . The message you intend to convey through words may be the exact opposite of ______ others actually understand.

A．why

B．that

C．which

D．what

9 . Wind power is an ancient source of energy ________ we may return in the near future.

A．on which

B．from which

C．by which

D．to which

10 .

Moving a Giant

The logistics of excavating(挖掘)and relocating a town's century-old, living sequoia(红 杉)tree. Inhabitants of Boise, Idaho, watched with trepidation earlier this year as the city's oldest, tallest resident moved two blocks. The 105-year-old sequoia tree serves as a local landmark, not only for its longevity but also because renowned naturalist and Sierra Club cofounder John Muir provided the original seedling. So, when Saint Luke's Health System found that the 10-story-tall conifer(针叶树)stood stood in the way of its planned hospital expansion, officials called tree-moving firm Environmental Design.

The Texas-based company has developed and patented scooping and lifting technology to move massive trees. Weighing in at more than 800,000 pounds, the Boise sequoia is its largest undertaking yet. "I (had) lost enough sleep over this," says David Cox, the company's Western region vice president—and that was before the hospital mentioned the tree's distinguished origin. Before the heavy lifting began, the team assessed the root system and dug a five-foot-deep cylinder, measuring 40 feet in diameter, around the trunk to protect all essential roots. After encapsulating the root ball in wire mesh, the movers allowed the tree to adapt to its new situation for seven months before relocating it. The illustration details what followed. —Leslie Nemo

1. Mark A. Merit and his team at Environmental Design installed underneath the root ball a platform of seven-inch-diameter, 44-foot-long steelbars and, just below the rods, a first set of uninflated airbags (shown in gray). The team also dug a shallow ramp.

2. In roughly 15 minutes, the movers inflated the airbags to about three feet in diameter to raise the root ball to the surface of the hole.

3. By underinflating the front bags, the team allowed the platform carrying the tree to roll up the ramp and out of the hole while staying level. A trailer hauled the tree along as team members removed the airbags from the back of the platform and replaced them in the front. They repeated the process until the tree arrived at the edge of its new home.

4. There a second set of partially inflated bags (shown in white) waited inside the hole. Soil surrounding the sequoia in its original location was relocated as well, because trees are more likely to survive a transplant when they move with their original soil.

5. Using the first set of airbags, the movers rolled the platform into the new hole.

6. The bags waiting there were then inflated further to take the weight of the sequoia while the transportation bags were deflated and removed from under the tree.

7. The white bags were then deflated in about half an hour to lower the sequoia's root ball to the bottom of its hole. The bags were removed, but the metal bars were left with the tree because they rust and degrade over a number of years.

8. For the next five years the local park service will monitor and maintain the tree in its new home.

1. Which of the following words can be used to replace the words underlined " stood in the way of" ?

A．Resisted.	B．Balanced.
C．Blocked.	D．Promoted.

2. What is the reason for the relocation of Sequoia trees?

A．Because the Scooping and lifting technology should be put into use.

B．Because it blocks local hospital expansion plans.

C．Because it corresponds to government’s plan of Environmental Design.

D．Because sequoia trees are over a hundred years old.

3. How will the migrated sequoia trees be dealt with?

A．They will be given new soil in the new living environment.

B．Metal rods used to move sequoia trees will not be left on the trees.

C．They will be kept in transport bags all the time.

D．They will be managed by specialists in the next five years.