1 . In early October, Travis Gienger transported an enormous pumpkin (南瓜) from his home in Minnesota to the World Championship Pumpkin Weigh-Off in California. His pumpkin set the record for the biggest one ever grown in North America. How do competitive growers get their pumpkins to grow to massive sizes?     1    

Gienger, who teaches horticulture (园艺学) at Anoka Technical College, begins growing his pumpkins in mid-April, starting with seeds that he grows indoors for the first few weeks, when Minnesota’s soil is too frosty.     2     They can absorb sunlight, nutrients from the soil, and water there. “At their peak, you’re watering them with at least 600 liters a day, ” he says.

Depending on the variety, pumpkin plants can grow up to a dozen fruits on a single vine (藤曼) . But to maximize size, growers remove all but one or two of these pumpkins in order to decrease each individual fruit’s competition for resources.     3    

But what exactly happens inside a pumpkin as it grows? Two factors drive natural growth: cell division and cell expansion. Cell division accounts for most of the growth at the beginning of a fruit’s life. This period lasts for about 20 days in pumpkin plants.     4     Pumpkin cells will expand until around 50 or 60 days after pollination (授粉).

    5     Some varieties of pumpkins have been bred specifically to maximize their size. Still, there is genetic variation even among pumpkins of the same variety. This has led to competition for the best seeds. Following each harvest, many growers auction off (拍卖掉) the seeds from their biggest pumpkins, which will then be used for the following year’s plantings.

A．Biology has the answers.

B．Genetics also influences pumpkin growth.

C．The following tips will give you a head start.

D．Once it warms up, the plants are transferred outside.

E．When it stops, cell expansion will then come into play.

F．Growers extend the growth period for as long as possible.

G．Growers also remove the weeds in the area for the same reason.

2 . 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。

The use of bamboo in science and technology is really exciting. In the Warring States period, Li Bing     1     (lead) the local people to build the Dujiang Weir, the first irrigation network in the world,     2     bamboo played an important role. During the Han dynasty, the Sichuan people successfully sank     3     1,600-meter-deep well with thick bamboo ropes. This technology didn’t spread to Europe     4     the 19th century and in 1859 Americans sank the first oil well in Pennsylvania by     5     (employ) the technology.

Papermaking     6     (be) one of China’s four ancient great inventions. In the Han dynasty, people began to use bamboo     7     (make) paper, which was of excellent quality and fair price. Even now it is considered as one of the important materials in papermaking. Some of the Xuan paper for traditional Chinese painting is also made     8     bamboo.

In the Yuan dynasty, a man     9     (plan) to send a person on the chair to space tied a big bamboo tube filled with gunpowder onto each of the four legs of a chair. Although it appears amusing, it is regarded as the     10     (early) “manned rocket design”.

3 . Every tree tells a story. They hold our memories, represent belief, and witness countless moments of joy and sorrow. In our imagination, there is always a place for a tree.

For the locals in Naunde, Mozambique, a mango tree provides more than just shade from the Saharan sun. It is also a traditional setting for storytelling, ceremonies, and regulating village life. “It is a place to meet and talk, to seek agreement and settle arguments, to bridge differences and develop unity,” wrote Kofi Annan, the former Secretary-General of the UN. “If you have a problem and can’t find a solution, you meet again tomorrow under the tree and you keep talking.”

The mango tree always stands there, witnessing and remembering everything, and at the same time becomes an inseparable part of the collective memory of the locals. “Each growth layer that trees add every year contains a bit of the air from that year. The trees absorb carbon dioxide from the air through tiny pores (气孔) , which helps build their tissues, so they physically hold the record of the years of their surroundings,” said Benjamin Swett, author of New York City of Trees. In this way, trees also serve as nature’s memory stick, keeping a record of a history as long as themselves.

The English language borrows a lot from trees: We turn over a new leaf and branch out, meaning we move on from the past and start something new. And there are times when we can’t see the wood for the trees. We tend to enjoy the flourishing leaves, branches, and roots of the trees. However, we pay little attention to the forests that embrace trees. The same things often happen to us in our own lives. We often dip ourselves into some bad experiences in life. As a result, we may give up at a terrible moment instead of imagining satisfying success after defeating the failure.

Trees inspire mankind, not just through language, but through ideas. Perhaps the most famous is a tree in a garden in Lincolnshire, England, where an apple fell and inspired young Isaac Newton to wonder: Why would that apple always fall directly to the ground? According to an   18th-century account, Newton was home from Cambridge when he stepped into the garden and into a reverie (沉思) . There, the idea of gravitation came into his mind, inspired by an apple.

1. What is the role of a mango tree in Naunde?

A．A spot to bind the locals together.	B．A witness to the changing weather.
C．A generous food supplier on Earth.	D．A shelter to protect villagers in disasters.

2. How do trees keep a record of their surroundings?

A．By changing the width of their growth layer.

B．By sticking out branches in different directions.

C．By absorbing carbon dioxide to build their tissues.

D．By reflecting changing climate conditions with their tiny pores.

3. What is the fourth paragraph mainly about?

A．Suggestions on facing failure.	B．Famous English stories about trees.
C．The relationship between trees and forests.	D．Lessons from English expressions related to trees.

4. Why does the author mention Newton in the last paragraph?

A．To explain the necessity of observation.	B．To show how gravitation was discovered.
C．To stress the importance of trees in inspiring ideas.	D．To introduce how trees serve as a mirror of history.

4 . The green and red watermelon is a sweet, refreshing summer snack. But it wasn’t always so sugary or brightly colored. So what did watermelons originally taste and look like, and from where did they come?

The fruit isn’t from the Fertile Crescent of ancient Mesopotamia, as so many other domesticated (家养的) crops are, research shows. Susanne Renner, a scientist, and her colleagues carried out comprehensive genetic sequencing (基因测序) of the domesticated watermelons — the kind you might find on supermarket shelves — along with six wild watermelon species.

“We found the modern genomes (基因组) of the domesticated watermelon are more closely related to the Sudanese wild type than any other that we analyzed,” she said. The Sudanese wild watermelon has some obvious differences from the domesticated version. “The flesh is white and not very sweet, and it’s mainly used as animal feed,” Renner said. Nevertheless, the genetic similarity between the two species led the researchers to conclude that the Sudanese fruit is probably a precursor (前身) to the red and sweet domesticated watermelon.

It’s likely that ancient farmers grew non-bitter varieties of the wild watermelon and thus increased its sweetness over many generations through the domestication process. The red color is probably also thanks to artificial selection, in which farmers likely favored and selectively bred red fruit.

We already knew that the ancient Egyptian king Tutankhamun was buried with watermelon seeds 3,300 years ago, yet that isn’t sufficient proof of a domesticated, sweet watermelon. But then, Renner found an image of a watermelon-like fruit on an ancient Egyptian tomb painting, thought to be more than 4,300 years old. In a separate tomb, another image showed the watermelon cut up in a dish alongside other sweet fruits. This realization, coupled with Renner’s genetic findings, suggests that the watermelon was most likely domesticated around that time either in Egypt or within trading distance of the ancient empire.

“Historically speaking, that’s a very significant finding,” said Hanno Schaefer, a professor of plant biodiversity. “It’s becoming clearer that we’ve greatly neglected the North African region. We’ve focused too much on the Fertile Crescent and we need to invest more resources into studying the agriculture of North Africa.”

1. What can we learn about the Sudanese wild watermelon?

A．It is brightly colored and sugary.

B．It is consumed mainly by animals.

C．It has no connection with the domesticated type.

D．It has more differences than similarities to the domesticated type.

2. What can be inferred from the text?

A．More resources will be devoted to agriculture research in South Africa.

B．The domesticated watermelon has a history of at least four thousand years.

C．The domesticated watermelon probably developed from the Sudanese type.

D．Few domesticated crops are from the Fertile Crescent of ancient Mesopotamia.

3. What is the fourth paragraph mainly about?

A．The history of the Sudanese wild watermelon.

B．Where wild watermelons actually come from.

C．The characteristics of domesticated watermelons.

D．How domesticated watermelons came into being.

4. What is Hanno Schaefer’s attitude towards Renner’s findings?

A．Favorable.

B．Doubtful.

C．Critical.

D．Tolerant.

5 . A lot of health care are connected with being around trees.     1     According to one 2015 study, a walk in the woods can make you feel seven years younger.

They also do a great deal of good for the environment by reducing air pollution and taking in carbon dioxide from the atmosphere.     2     A new study by researchers at University College London found that the trees in the London Borough (自治市) of Camden store as much carbon per hectare (公顷) as rainforests.

A tree’s ability to take in carbon dioxide is especially useful when the tree.is in cities or towns, where there are too many industrial activities. For the study, the researchers used laser scanning methods to take their own carbon readings of trees from the ground as well as the air.     3     They were able to know there are about 85,000 trees in Camden, where the university is based.

They determined that Camden had a median carton density (浓度) of around 55 tons of carbon per hectare (t/ha). Greener areas of the borough, like Highgate Cemetery, had a carbon density of 380 t/ha — levels that are typically seen in rainforests.     4    

So what exactly does this mean? Trees could help cool the atmosphere by removing carbon dioxide from the air. However, some climate scientists argue that it’s more complicated (复杂的) than that.     5     Still, with all of the other benefits trees offer, planting a seed or two couldn’t hurt.

A．We need to protect the ones we already have.

B．Global warming is happening at a faster rate than ever.

C．These benefits aren’t just felt in the countryside, either.

D．For comparison, major cities in the US have a carbon density of 7.7.

E．They have been known to reduce people’s stress and improve overall mental health.

F．Then they compared their findings with the data from the UK Environment Agency.

G．They think the impact of tree-planting activities today may not be seen for many years.

6 . Common water plant could provide a green energy source. Scientists have figured out how to get large amounts of oil from duckweed, one of nature’s fastest-growing water plants. Transferring such plant oil into biodiesel (生物柴油) for transportation and heating could be a big part of a more sustainable future.

For a new study, researchers genetically engineered duckweed plants to produce seven times more oil per acre than soybeans. John Shanklin, a biochemist says further research could double the engineered duckweed’s oil output in the next few years.

Unlike fossil fuels, which form underground, biofuels can be refreshed faster than they are used. Fuels made from new and used vegetable oils, animal fat and seaweed can have a lower carbon footprint than fossil fuels do, but there has been a recent negative view against them. This is partly because so many crops now go into energy production rather than food; biofuels take up more than 100 million acres of the world’s agricultural land.

Duckweed, common on every continent but Antarctica, is among the world’s most productive plants, and the researchers suggest it could be a game-changing renewable energy source for three key reasons. First, it grows readily in water, so it wouldn’t compete with food crops for agricultural land. Second, duckweed can grow fast in agricultural pollution released into the water. Third, Shanklin and his team found a way to avoid a major biotechnological barrier: For the new study, Shanklin says, the researchers added an oil-producing gene, “turning it on like a light switch”by introducing a particular molecule (分子) only when the plant had finished growing. Shanklin says, “If it replicates (复制) in other species-and there’s no reason to think that it would not — this can solve one of our biggest issues, which is how we can make more oil in more plants without negatively affecting growth.”

To expand production to industrial levels, scientists will need to design and produce large-scale bases for growing engineered plants and obtaining oil — a challenge, Shanklin says, because duckweed is a non-mainstream crop without much existing infrastructure (基础设施).

1. What can people get from duckweed firsthand?

A．Plant oil.	B．Stable biodiesel.
C．Sustainable water.	D．Natural heat.

2. What does paragraph 4 mainly convey?

A．Options for renewable energy.

B．Reasons for engineering genes.

C．The potential of revolutionary energy source.

D．The approach to avoiding agricultural pollution.

3. What is the decisive factor to mass-produce the plant?

A．Industrial levels.	B．Unique design.
C．Academic research.	D．Basic facilities.

4. What would be the best title for the text?

A．Duckweed Power	B．Duckweed Production
C．Genetic Engineering	D．Genetic Testing

7 . 听下面一段独白，回答以下小题。
1. What are the good seeds confirmed by?

A．Containers.

B．X-rays.

C．Freezers.

2. Why are seeds stored in frozen environment?

A．To be preserved for long.

B．To tackle climate change.

C．To safeguard food supply.

3. What is the speech mainly about?

A．Where seeds are stored.

B．How the seed bank works.

C．Why seed banks are important.

8 . You’ll only find cherry blossoms in a handful of countries.

Called sakura in Japan, the cherry blossoms of Yoshino and Kyoto are world-famous. Tourists flock to the country each spring to try their hand at a centuries-old activity “flower viewing”. You don’t have to fly to Japan to see them, though. In the US, the cherry blossoms of Washington, D.C., New York City, Philadelphia, St. Louis, Seattle, San Francisco, and Boston are all beautiful in their own way. The flowers can also be viewed in many European and Asian countries, as well as Brazil and Australia in the southern hemisphere.

There are hundreds of cherry tree varieties.

Japan in particular is home to hundreds of types of cherry trees -possibly more than 600.Some types bear fruit, while others don’t. The flowers of many trees change from dark pink to light pink to white throughout the different stages of blossoming, while others progress from greenish yellow to white to pink. One variety, called Kanzan, was bred to have “double blossoms” — or up to28 petals (花瓣) on each flower, compared to the Yoshino tree’s five petals.

You can get arrested for picking a cherry blossom in Washington, D. C.

Resist the urge to take a cherry blossom home with you as a souvenir. In D.C. at least, breaking off a blossom or branch is viewed as destruction of federal property. Those who break this rule could receive a citation (传票), or worse, be arrested. It goes without saying that it’s also illegal to climb the trees. If they sustain damage to their branches, they will never be able to grow new blossom on that particular branch again.

Both the blossoms and leaves are edible.

In Japan, no part of the cherry blossom tree pes to waste. The preserved leaves are used as edible mochi wrappers (a rice cake filled with sweet bean paste), and a number of seasonal snacks feature sakura as a key ingredient Sakura-flavored versions of Pepsi, Coke, tea, and even Starbucks lattes are all popular drinks. You can also find Kit Kats and Pocky snack sticks that taste like sakura.

They were the inspiration behind a record-setting LEGO sculpture.

Legoland Japan, a theme park in Nagoya, set a Guinness World Record in 2018 for the largest LEGO brick cherry blossom tree ever made. The trees stood 14 feet tall, weighed over 7000 pounds, and consisted of more than 800,000 LEGO bricks.

1. In which country can’t you see cherry blossoms according to the passage?

A．America.

B．China.

C．Germany.

D．Egypt

2. What can be learned from the passage?

A．Climbing cherry trees is tolerable in Washington.	B．Sakura-flavored snacks and drinks are welcomed.
C．Kanzan sakura is better than Yoshino sakura.	D．The largest cherry blossom tree grows in Japan.

3. Who is the article meant for?

A．A passionate environmentalist.	B．An ecological researcher.
C．A student interested in plants.	D．A tourist in Japan

9 . Scientists have shown how plants can protect themselves against genetic (基因的) damage caused by environmental stresses. The growing tips of plant roots and shoots have an in-built mechanism (机制) that spells cell death if DNA damage is detected, avoiding passing on faulty DNA.

Plants have small populations of stem cells (干细胞) at the tips of their roots and shoots, which enable them to continuously grow and produce new tissues throughout their lifetime. These stem cells serve as ancestors for plant tissues and organs. However, any genetic faults present in the stem cells will continue to exist and be passed on permanently throughout the plant’s life, which could last thousands of years.

Given the critical role of stem cells and their exposure to potentially dangerous environments at the growing tips of roots and shoots, safeguards are necessary to prevent stem cell faults from becoming fixed. Researchers Nick Fulcher and Robert Sablowski, funded by the Biotechnology and Biological Sciences Research Council, aimed to uncover these protective mechanisms. Through experiments involving X-rays and chemicals, they discovered that stem cells were more sensitive to DNA damage compared to other cells.

When DNA damage occurs, the cells have the capacity to detect it and cause programmed cells to die, preventing the propagation of the damaged genetic code to the rest of the plant tissues. This process has similarities to the safeguard mechanism found in animal cells, which has been broadly studied due to its relevance in preventing cancer.

The identification of a similar protective system in plants is of great interest in the field of plant development. It also helps scientists develop plants that can better handle environmental stress. So knowledge of how plants deal with these stresses is of fundamental significance to agricultural science’s response to climate change.

1. What is the function of the in-built mechanism in plants?

A．To produce more roots and shoots.	B．To increase the overall lifetime of the plant.
C．To enhance plant growth and nutrient intake.	D．To stop genetic faults in stem cells passing on.

2. What can we know about stem cells in plants according to the text?

A．They are relatively abundant in quantity.	B．They are resistant to environmental stresses.
C．They make quick response to DNA damage.	D．They have the ability to repair damaged DNA.

3. What does the underlined word “propagation” in paragraph 4 mean?

A．Spread.

B．Change.

C．Existence.

D．Self-repair.

4. What does the last paragraph focus on?

A．The way of dealing with climate change on the earth.

B．The significance of identifying the protective system in plants.

C．The method of ensuring plant survival under environmental stress.

D．The urgency of developing plants that can handle environmental stress.

10 . When micro-plastics end up in farm fields, the pollution can damage plant growth. But two young researchers now report that combining fungi (真菌) with certain farm wastes can partly overcome that problem.

May Shin, 20, and Jiwon Choi, 18, met in a research design class at the Fryeburg Academy, a high school in Maine. May had desired to explore how micro-plastics might affect the ecosystem. Jiwon was crazy about plants and fungi. The young scientists cooperated to test how long-lived plastics might affect farm crops.

Scientists have shown certain fungi can aid root growth and a plant’s nutrient uptake. Those organisms are named arbuscular mycorrhizal fungi (AMF). Certain farm wastes, like straw, can provide nutrients to plants and help stabilize their roots. Such wastes are also known as mushroom substrate (基质) and people often grow mushrooms in them.

May and Jiwon planted over 2,000 scallion (大葱) seeds in pots of soil. Half the seeds got soil polluted with micro-plastics. The rest grew in plastic-free soil. The plants then were further divided into four groups. The young scientists added AMF to the soil in one group. Another group had a top layer of mushroom substrate. A third group got both treatments. The last group got none. For three weeks, the pair tracked how many scallions sprouted (发芽) in each group and measured the plants’ height once each week.

About twice as many scallions sprouted in clean soil compared to that containing plastic bits. But among plants surviving in the polluted soil, a combination of AMF and mushroom substrate helped them out. Those getting both treatments grew 5.4 centimeters per week. That was faster than either of the treatments alone or those getting none.

Jiwon and May then looked at the plant roots with a microscope. Where AMF had been added, it grew into those roots. That increased the scallion roots’ surface area, May said, which should promote their uptake of nutrients. So “I see this project as coming up with a sustainable solution for plant growth in polluted soils,” said May.

1. Why did May and Jiwon work together?

A．To see the effects of long-lived plastics on farm crops.

B．To find the relationship between plants and fungi.

C．To design a research on the growth of plants.

D．To explore the way that the ecosystem works.

2. What is the author’s purpose in writing paragraph 3?

A．To prove the existence of micro-plastics.	B．To compare fungi with farm wastes.
C．To tell the advantages of farm wastes.	D．To provide some related information.

3. What aspect of the study is the fourth paragraph mainly about?

A．Its purpose.

B．Its design.

C．Its findings.

D．Its reasons.

4. How can AMF and mushroom substrate make plants grow faster?

A．By keeping the plants more resistant to pollution.	B．By allowing the plants’ deep area more freedom.
C．By making nutrients more available to the plants.	D．By exposing the roots to a larger surface area.