The entire global population of marbled crayfish (龙纹虾) has been traced to a single female held in a German aquarium (水族馆), which was born with the ability to reproduce without males. Every marbled crayfish is female, and every egg laid is an exact clone of its mother. The ability to reproduce quickly with such ease made them popular in the aquarium trade, but when they found their way into the wild, the crayfish got out of control.
The first known marbled crayfish appeared in 1995. Since then, they have spread into the wild and populated in freshwater ecosystems around the world. Scientists studying this animal have raised the alarm about its likely influence on local wildlife, ecosystems and agriculture as it spreads into new environments. Successful non-native species like the marbled crayfish often cause trouble when they arrive in new environments, as they can feed on local wildlife or compete with it for resources.
According to Dr Frank Lyko, a researcher at the German Cancer Research Centre, the first marbled crayfish appeared due to a sudden change in its parents’ cells. It was an animal that reproduces clonally and therefore represents a model of a central aspect in tumor (肿瘤) development.
“Tumor genomes (基因组) also develop clonally, because they go back to a single original cell,” he said. However, both crayfish and tumors are still able to adapt to their environments through a process termed “clonal evolution”, and in both cases this can be harmful. In crayfish, their ability to adapt means they can spread to a variety of different environments and climates, and in tumors this means they can develop resistance (抵抗) against cancer-targeting drugs.
At present, with the potential influence of the increasing marbled crayfish on local places, governments from different places are working on controlling their population.
1.What does the text say about marbled crayfish in the wild?
A.They prove popular. B.They are under control.
C.They can be troublesome. D.They are out of condition.
2.What does Dr Frank Lyko try to explain?
A.The reason for marbled crayfish’s clonal reproduction.
B.The similarities between marbled crayfish and tumors.
C.The way to stop marbled crayfish cloning themselves.
D.The harmful influence marbled crayfish have on health.
3.What are governments doing about marbled crayfish now?
A.Working on removing all of them. B.Trying to limit the quantity of them.
C.Taking control of them with drugs. D.Connecting them with harmful tumors.
4.What can be a suitable title for the text?
A.Why Marbled Crayfish Reproduce Rapidly
B.The Population of Marbled Crayfish Is Huge
C.The Spread of Marbled Crayfish Is Worrying
D.How to Control the Number of Marbled Crayfish
On an island in northern Norway, the sun doesn’t set from May 18 right through to July 26. The locals, having spent the long polar night from November to January, when the sun doesn’t rise at all, make the most of these months, with no regard to conventional timekeeping. The island intends to exchange its watches for flower garlands (花环) and declare itself the world’s first time-free zone (地区).
“There’s constant daylight, and we act accordingly,” says islander Kjell Ove Hveding in a statement. “In the middle of the night, which citizens might call ‘2 am’, you can spot children playing soccer, people painting their houses or mowing their lawns (草坪), and teens going for a swim.”
Now they want to make it official. Islanders gathered at a town hall meeting to sign a petition (请愿) for a time-free zone and on June 13, Hveding met with a Norwegian member of parliament (国会) to hand over the locals’ signatures and to discuss the practical and legal challenges.
“To us, getting this in writing would simply mean formalizing something we have been practicing for generations,” he says.
Islanders hope to be free of traditional opening hours and to introduce flexibility in school and working hours. Fishing and tourism are the main industries on this island with a population of little more than 300 people. Local fisher and women often spend days on the ocean for their catch, with little regard to timetable.
It’s clear that they mean business. When visitors cross the bridge to the island from the airland, they aren’t greeted with padlocks (symbolizing love locks) like on similar bridges worldwide. The bridge is covered with watches, as people prepare for entry to the land time forgot.
1.What do the islanders normally do at midnight from May 18 to July 26?
A.Struggle with strong light. B.Sleep like outside people.
C.Turn watches into flowers. D.Do daily work or have fun.
2.According to Hveding, the islanders’ living a life free of time ________.
A.is difficult to describe B.proves practical and legal
C.is a new kind of lifestyle D.has been a long tradition
3.What does the author mean by “they mean business” underlined in the last paragraph?
A.The islanders are serious about being free of time.
B.The islanders intend to treat tourism as business.
C.Visitors are ready to enter a time-free island
D.Visitors actually prefer watches on bridges.
4.What is the main idea of the text?
A.Islanders in Norway have been free from time.
B.An island wants to be a time-free zone officially.
C.It’s time to lead a life without the limit of time.
D.An island won’t be open to the world any longer.
Cruz Genet, 11, and Anthony Skopick, 10, couldn’t agree. Were the birds out on the ice ducks or geese? So on a cold January evening last year, the two friends ventured (冒险) onto the frozen pond near their homes in Frankfort, Illinois, to get a better look. First, they threw a rock onto the ice to test it, Cruz told NBC 5 Chicago. “Then we stepped on it.” Convinced the ice would hold their weight, Anthony took a few steps, but then he fell through the seemingly frozen surface.
Cruz rushed to help his panicked friend. However, the pond swallowed him, too. Cruz managed to lift himself out of the extremely cold water and onto a more solid section. He then gingerly worked his way toward Anthony. But the ice didn’t hold, and he fell in again. This ime, he couldn’t get out.
The boys were up to their necks in icy water and quickly losing feeling. Any chance of their freeing themselves was slipping away. Cruz was sure that he was going to die.
Anthony’s older sister had seen the boys fall through the ice and started screaming, wishing someone to save them.
John Lavin, a neighbor driving nearby on his way to the grocery store, heard her. He quickly pulled over. Seeing the boys, he grabbed (抓住) a nearby buoy (救生圈), kicked off his shoes, and ran into the cold water, struggling his way through the ice. Lavin made his way to Cruz and Anthony and pulled them back to land.
The boys were taken to the hospital, where doctors discovered that their five- minute stay in the water had lowered their body temperature nearly ten degrees. Fortunately, they have fully recovered, though they are still a little amazed by their fearless neighbor. “Just to think,” says Cruz, “if he hadn’t been there, I could have died.”
1.Why did the boys venture onto the frozen pond?
A.To have a better look at the frozen pond.
B.To catch the birds in the pond with rocks.
C.To find out what the birds on the ice were.
D.To test the thickness of the ice in the pond.
2.What does the underlined word “gingerly” in paragraph 2 probably mean?
A.Casually. B.Proudly.
C.Firmly. D.Cautiously.
3.What drew John Lavin’s attention to the boys?
A.Anthony’s older sister’s cry for help. B.Cruz’s loud and frightening scream.
C.Their shoes along the nearby pond. D.Their neighbors’ pulling them back.
4.Which of the following words can best describe John Lavin?
A.Hard-working and helpful. B.Warm-hearted and courageous.
C.Curious and selfless. D.Active and generous.
The following places will give you an unexpected travelling experience.
Svalbard
If you’re a fan of winter activities, but in need of some sun, then perhaps a May trip to Svalbard is in order. Svalbard is located about 620 miles south of the North Pole. In late spring, the sun never dips below the horizon, and it means you can take in all the Vitamin D you desire for. Popular activities in the area include hiking and wildlife spotting.
Namibia
During spring, Namibia is considered as the perfect destination with reduced travel costs and cooler evenings. National Geographic Travel says that the watering holes start to dry up again in late May, which attracts giraffes and black rhinos from their hiding spots. If you’re more of an adventurous explorer, head to the Namib Desert for a spot of sand boarding on the dunes (沙丘).
Japan
If you want to catch the wonderful cherry blossom season in Japan, National Geographic Travel says you should head there between January and May. Recommended activities include taking a dip in the hot springs in Kawazu and boating down the Kitakami River to Tenshochi Park where 10,000 cherry trees turn into charming pale pink avenues.
Upper Amazon, Peru
For travelers looking for a sense of adventure, National Geographic Travel proposes a trip to the upper Amazon in Peru. It notes that by May, the water levels will have increased, allowing for improved navigation and cooler temperatures.
1.Which place is fit for visitors fond of desert adventures?
A.Svalbard. B.Namibia
C.Japan. D.Upper Amazon, Peru.
2.What can you do when travelling in Tenshochi Park in May?
A.Plant cherry trees. B.Swim in the hot springs.
C.Enjoy beautiful flowers. D.Take a boat on the river.
3.Which month is the best time for people to visit the four places?
A.May. B.March.
C.April. D.February.
请认真阅读下面有关我国出国留学低龄化现象的图表及相关文字,并按照要求用英语写一篇150词左右的文章。
(写作内容)
1. 用约30个单词概述两张图表信息的主要内容;
2. 出国留学低龄化的原因有哪些,简要谈谈你的看法(上述文字信息仅供参考,原因不少于两点);
3. 作为高中生,你会选择在国内上大学还是出国留学?请简要说明理由(不少于两点)。
(写作要求)
1. 表明个人观点,同时提供理由或论据;
2. 阐述观点或提供论据时,不得直接引用原文中的句子;
3. 文中不能出现真实姓名和学校名称;
4. 不必写标题。
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请认真阅读下列短文,并根据所读内容在文章后表格中的空格里填入一个最恰当的单词。注意:每个空格只填1个单词,请将答案写在答题卷上相应题号的横线上。
Could a Doodle (涂鸦)Replace Your Password?
Nearly 80 percent of Americans own a smartphone, and a growing proportion of them use smartphones to surf the Internet, not just when they’re on the go. This leads to people storing considerable amounts of personal and private data on their mobile devices.
Often, there is just one layer of security protecting all that data--emails and text messages, social media profiles, bank accounts and credit cards, even other passwords to online services. It’s the password that unlocks the smartphone’s screen. Usually this involves entering a number, or just laying a fingertip a sensor.
Over the past couple of years, my research group, my colleagues and I have designed, created and tested a better way. We call it “user-generated free-form gestures,” which means smartphone owners can draw their own security pattern on the screen. It’s a very simple idea that is surprisingly secure.
1. IMPROVING TODAY'S WEAK SECURITY
It might seem that biometric (生物识别的) authentication (认证), like a fingerprint, could be stronger. But it’s not, because most systems that let a user allow fingerprint access also require a PIN (Personal Identification Number) or a password as a backup method. A user or thief could skip the biometric method and instead just enter (or guess) a PIN or a password. Compared to other methods, our approach dramatically increases the potential length and complexity of a password. Users simply draw a pattern across an entire touchscreen, using any number of locations on the screen.
2. MEASURING DRAWINGS
As users draw a shape or pattern on the screen, we track their fingers, recording the directions and speed. We compare that track to one recorded when they set up the gesture-based login. This protection can be added just by software changes; it needs no specific hardware or other modifications to existing touchscreen devices. As touchscreens become more common on laptop computers, this method could be used to protect them too.
Our system also allows people to use more than one finger — though some participants wrongly assumed that making simple gestures with multiple fingers would be more secure than the same gesture with just one finger. The key to improving security using one or more fingers is to make a design that is not easy to guess.
3. EASY TO DO AND REMEMBER, HARD TO BREAK
Some people who participated in our studies created gestures that could be articulated as symbols, such as digits, geometric shapes (like a cylinder) and musical notations which are easy for them to remember. Even a relatively simple symbol, like an eighth note, can be drawn in so many different ways that calculating the possible variations is computationally intensive and consumes plenty of time. This is unlike text passwords, for which variations are simple to try out.
4. REPLACING MORE THAN ONE PASSWORD
Our research has extended beyond just using a gesture to unlock a smartphone. We have explored the potential for people to use doodles instead of passwords on several websites. Unappeared to be easier to remember multiple gestures than it is to recall different passwords for each site.
In fact, it was faster. Logging in with a gesture took two to six seconds less time than doing so with a text password. It’s faster to generate a gesture than a password, too. People spent 42 percent less time generating gesture credentials than people we studied who had to make up new passwords. We also found that people could successfully enter gestures without spending as much attention on them as they had to with text passwords.
Gesture-based interactions are popular and prevalent on mobile platforms, and are increasingly making their way to touchscreen-equipped laptops and desktops. The owners of those types of devices could benefit from a quick,easy and more secure authentication methods like ours.
Could a Doodle Replace Your Password? | ||
Passage outline | Detailed information | |
Introduction | •An increasing number of people use smartphones for Internet1.The free-form gesture drawn with a doodle is a very simple but surprisingly secure idea. | |
Characteristics | Improving today’s weak security. | •A user or thief could skip fingerprint authentication by employing an2.like just guessing a PIN or a password. •In3. to other methods, the passwords our approach is dramatically longer and complex than that of other methods. |
Measuring drawings | •A shape or pattern drawn on the screen, where the user's fingers go and 4.quickly they move. •To make a design with one or more fingers that is difficult to guess is of great 5.to the improvement of security. | |
Easy to do and remember, hard to break | •Even a relatively simple symbol can be drawn in diverse ways so that the6. of the possible variations is intensive and time-consuming. | |
7. the place of more than one password | • It is more8.to recall different password for each site than to remember multiple gestures. •Having new passwords9.takes 42 percent more time than generating gesture credentials with a doodle. | |
Conclusion | •Gesture-based interactions are gaining10.and are widely applied to touchscreen-equipped laptops and desktops. |