1 . On the streets of Manhattan and Washington, D. C., in neighborhoods in Seoul and parks in Paris, ginkgo (银杏) trees are losing their leaves in reaction to the first gust of cold winter air. This leaf drop, gradual at first, and then sudden, carpets streets with golden, fan-shaped leaves. Scientists are documenting evidence of the event happening later and later, a possible indication of climate change. But the story of ginkgos is not the familiar one of human carelessness with nature.
Thanks to fossils found in North Dakota, scientists found a ginkgo has genetically similar ancestors dating back 170 million years to the Jurassic Period. “It almost went extinct. Then humans rescued it and spread it around the world. It’s such a great evolutionary (进化) and cultural story,” says Peter Crane, a ginkgo expert.
One theory for the decline of the ginkgo species began 130 million years ago, when flowering plants began spreading. They grew faster and attracted more pollinators (传粉者) than ginkgos. “It’s possible that ginkgos were elbowed out of the way,” says Crane. Already competing to survive, ginkgos began to disappear during a time of global cooling that began around 66 million years ago. By the time the last ice age ended 11,000 years ago, the remaining survivors were found in China.
Ginkgo trees are smelly. “My guess is that they were eaten by animals that liked smelly things. They then passed through their body and grew.” Crane says. Those same seeds may have helped ginkgo find favor with humans 1,000 years ago. Once cleaned of their outer layer, ginkgo seeds are safe to eat. It’s then, when the trees had long since disappeared elsewhere, that people in China may have begun planting them and eating their seeds. Then gradually ginkgos spread across the world. Now it’s seemingly naturally resistant to insects and high levels of air pollution.
Crane isn’t worried about its future, though: The popularity of the species will help it survive. “Though its status in the wild may be difficult to access, it’s a plant that’s unlikely to ever go extinct,” he says.
1. What may have caused the further delay of ginkgo’s leaf drop?| A．The colder weather in winter. |
| B．The protection from city councils. |
| C．The global warming phenomenon. |
| D．The careless interaction with humans. |
| A．The reasons why ginkgos almost died out. |
| B．The advantages of ginkgos over other plants. |
| C．The theories of experts for multiplying ginkgos. |
| D．The competition between various flowering plants. |
| A．Their eatable seeds. | B．Their unpleasant smell. |
| C．The natural evolution. | D．The careful planting. |
| A．Worried. | B．Optimistic. | C．Uncertain. | D．Hopeless. |
2 . Now, a study proves that gardens are more than just a pretty place. The study, by researchers at Illinois State University, demonstrates that such constructed gardens can have a measurable and positive impact on water quality.
Floating gardens are essentially platforms built and wrapped in coconut husks (椰子壳), and filled in with native plantings. As plants grow, they extend their roots into the water. On the North Branch of the Chicago River, non-profit Urban Rivers and its partners are developing a mile-long floating eco-park called the Wild Mile. The re-development of this former industrial canal is Urban Rivers’ important project. As part of the park, floating gardens, attached to shore, are being fixed.
The primary aim of the floating gardens is beautification. But the Illinois State team, from the University’s Department of Geology, Geography, and the Environment, saw an ideal setup for a controlled experiment. “We joined it because it’s the perfect opportunity to see if there’s an influence on water quality,” explains lead author Abigail Heath.
The study is novel: previous studies have explored floating gardens’ influence on water quality over time, primarily in wastewater treatment ponds, but not over space, in moving water. The project also matches well with Urban Rivers’ broader goals. “The city is interested in bettering water quality,” says Phil Nicodemus, Urban Rivers’ Director of Research. “Happily, Illinois State took part in it later.”
Could this small human-made park improve water quality? An average of data collected over the course of the study shows middle but definitive improvement. For example, nitrogen (氮) dropped from 4.69 milligrams per liter in surface water to 4.43 milligrams per liter, a drop of about 1 percent.
“Despite how small this garden was, there was measurable improvement in water quality from upstream to downstream,” notes Heath. She and her colleagues see this as a model for how large floating gardens should be to help improve water in similar settings. “Even this tiny garden makes a difference,” she says.
1. What can be inferred from the second paragraph?| A．The floating gardens are environmentally friendly. |
| B．The floating gardens are fixed everywhere in the eco-park. |
| C．The floating gardens can help fix the former parks. |
| D．The Urban Rivers were once industrial canals. |
| A．To reduce waste water. | B．To attract more visitors to the park. |
| C．To make the surroundings brilliant. | D．To help researchers do the experiment. |
| A．The floating garden. | B．The project. |
| C．The treatment of ponds. | D．The quality of water. |
| A．Floating Gardens: More than Pretty |
| B．The Best Way to Better Water Quality |
| C．A Practical Method of Improving Parks |
| D．Floating Gardens Beautify the City |
With high yield and superior quality, Chinese hybrid rice varieties have been introduced around the world,
In the past 40 years, Chinese scientists
Yuan Longping,
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4 . In 2010, Barack Obama was to pay a visit to Mumbai’s Gandhi Museum, where palm(棕榈)trees full of me dotted the grounds. The president knew me well-coconuts (椰子)are a part of life in Indonesia, where he spent his boyhood. Before his visit, Indian authorities, however, removed every last sign of me around the museum. They were afraid the president of the United States would be taken out by one of me falling on his head.
Let’s get this out of the way: My reputation as the “killer fruit” of countless innocents was then and still is a misbelief. A repeatedly misinterpreted 1984 study overstated the number of deaths I caused by hitting people on the head, and the word spread. Today, the only things about me “to die for” are the sometimes too-delicious foods you humans make with me, such as cookies and pies. A decade ago, health experts briefly gave me a halo because some of my fats may raise beneficial cholesterol (胆固醇). But ask a heart doctor today and they’ll tell you that coconut oil will raise your bad cholesterol as much. Death by coconut, indeed!
People have other wrong ideas about me. But allow me to leave you with a sweet presidential tale. A World War II boat commanded by one John F.Kennedy was destroyed in 1943 by a Japanese warship. Kennedy and his surviving crew were stuck on an island. They were suffering from hunger, thirst and injuries when they met two friendly native coast-watchers. Kennedy scratched a message into a coconut shell: “NAURO ISL...COMMANDER...11 ALIVE...NEED SMALL BOAT...KENNEDY.”
The coast-watchers delivered this successfully and all the crew were saved. Years later, the coconut shell was given to the newly elected president. It sat on his office desk throughout his presidency and now is a center-piece of the John F.Kennedy Library in Boston-as the proof that we coconuts don’t take lives, we save them.
1. Why did Indian officials get rid of “me”?| A．To reduce Obama’s fear. | B．To avoid unexpected injuries. |
| C．To show their welcome tradition. | D．To follow the request from the US. |
| A．thought little of me | B．did great damage to me |
| C．made me well-known | D．brought me a good name |
| A．Amusing. | B．Anxious. |
| C．Concerned. | D．Romantic. |
| A．To show a new discovery. | B．To correct people’s misbelief. |
| C．To tell the history of coconuts. | D．To describe a successful rescue. |
5 . What is the smelliest fruit on earth? Durians (榴莲), of course. But what makes this large spiky fruit from Southeast Asia so smelly? A team of researchers discovered the answer to this question recently. Their study explained which genes (基因) are responsible for the fruit's unique smell.
Thanks to the work of the scientists, we finally know why durians smell so unique. It's because of a gene called MGL，which can be found in other crops like cacao and cotton. Unlike other fruits that have just one copy of the gene, the durian has four, which are activated when the fruit is ripe.
According to the study, the MGL genes are involved in sulfur (硫磺) production. Indeed, they are the secret code to unlocking the smell of durians. In the wilderness, the smell serves an important purpose - survival. The fruit's special smell attracts animals, which eat and spread its seeds.
But of course, humans don't do this. So why do so many of us enjoy eating this unusual fruit? “It has a very rich and creamy taste. To us, it has a heavenly smell, and it melts in your mouth,” said professor Bin Tean Teh, the leading author of the study.
In some Southeast Asian countries where durians grow, the smelly fruit is not allowed on public transport and in many hotels. By identifying this MGL gene, scientists believe they could produce durians that don't smell as strong. This could increase its popularity. Those who hate it may love it, and those who love it may love it more.
However, not everyone is happy about the possibility of changing the smell of their favorite fruit. “A durian without its smell is nothing but an empty shell without its properties,” wrote Singaporean Richie Liang.
1. What did the study find?| A．Why people don't like durians | B．What kind of fruit smells good |
| C．How we make durians smell better | D．Which genes make durians smelly |
| A．The benefits of eating durians | B．The code to unlocking the MGL genes |
| C．The function of durians' smell | D．The disadvantage of the MGL genes |
| A．Smelly | B．Odd | C．Inviting | D．Familiar |
| A．To help them survive better | B．To make them more attractive |
| C．To increase their profits | D．To protect them from harmful insects |
| A．Opposed | B．Doubtful | C．Unconcerned | D．Supportive. |
