Coronaviruses are a large group of viruses. They consist of a core of genetic material(遗传物质) surrounded by an envelope with protein spikes(蛋白棘突). This gives it the appearance of a crown. Crown in Latin is called "corona" and that's how these viruses get their name. In this text, we'll take a quick look at what's currently known about the virus.

Covid-2019

    The 2019 Novel Coronavirus, first reported December in Wuhan, central China's Hubei Province, has quickly spread across the country and around the world. It initially occurred in a group of people with pneumonia (肺炎) who'd been associated with a seafood and live animal market in the city of Wuhan. 

    Intermediate hosts: The Covid-2019 may originate in bats, a team led by renowned Chinese virologist Shi Zhengli said earlier, while the intermediary host remains unknown.

    Incubation period(潜伏期): usually 1-14 days.

Infection: Virus may spread before symptoms show.

SARS-CoV

    The Severe Acute Respiratory Syndrome (SARS) coronavirus was first identified in China in 2003 .

    Intermediate hosts: Bats are the original host. Civet cats serve as an important intermediary that carries virus from the winged mammal to humans.

    Incubation period: 2-7 days.

    Infection: Virus spread after symptoms show.

MERS-CoV

    The Middle East Respiratory Syndrome (MERS中东呼吸综合征) coronavirus was first identified in Saudi Arabia in 2012.

    Intermediate hosts: MERS-CoV was travelled from dromedary camel to humans.

    Incubation period: 2-14 days.

    Infection: Virus may spread before symptoms show.

    In the trailer (拖车式房屋), Sischo was refreshing the snails'(蜗牛)accommodations--an  ongoing routine that takes days of careful work. He had found a dozen of Achatinella bulimoides--a third of the world's population of the species. Once every individual was accounted for, he cleaned the cage and packed in new leaves. The work took much trouble, but the responsibility, he said, was like "a heavy weight sitting on you."

    The trailer is very vulnerable. It's designed to keep away would-be thieved, and to resist hurricanes. But a fire could easily destroy it, or a disease could sweep through it. Last September , a mystery pathogon(病原体)appeared to have entered the trailer on leaves fed to the snails, killing almost the entire species. As sad as the event was, there's no good way to insure against future catastrophe. The snails can't simply be spread among zoos or other facilities: they need special equipment, experienced handlers, and a diet of native Hawaiian plants.

    Consequently, it can be hard for the snails' caretaker to relax, even when he is outside the trailer. “How do you switch off when your decisions mean existence or extinction?" Sischo said. While action lightens the burden, yet with animals whose natural history is largely unknown, that action can be dangerous. "If you do it wrong, the snails die."

    Snails are neither intelligent nor beloved. Sischo's friends sometimes tease him about being "the strange snail guy; strangers ask why he cares. It's hard to convince people, but he insists that if he can just get them in the trailer, they will understand why the Achatinella bulimoides are worth saving. "People melt," he said," When you show them that the entire population is in this chamber, it hits them."

    In the old days, when you had to drive to a movie theater or to a video store to get some entertainment, it was easy to see how your actions could have an impact on the environment. You were hopping into your car, driving across town and coughing out emissions(排放)and using gas all the way.

    But now that we're used to staying at home and streaming movies, we might get a little cocky. After all, we're just picking up our phones or maybe turning on the TV. You're welcome. Mother Nature.

    Not so fast, says a recent report from the French-based Shit Project. Watching a half-hour show would lead to 3.5 pounds of CO2 emissions. That's like driving 3.9 miles. According to "Climate Crisis: The Unsustainable Use of Online Video," digital technologies are responsible for 4% of greenhouse gas emissions, and that energy use is increasing by 9% a year. Stored in data centers, videos are transferred to our terminals such as computers, smart phones, etc. via networks. All these processes require electricity whose production consumes resources and usually involves CO2 emissions.

    In the European Union, the Eureca project lead scientist, Rabih Bashroush, calculated that 5 billion downloads and streams of the song "Despacito" consumed as much electricity as the countries of Chad, Guinea-Bissau, Somalia, Sierra Leone and the Central African Republic used in a single year.

    Streaming is only expected to increase as we become more attached to our devices. Online video use is expected to account for 80% of all internet traffic by 2022 according to CISCO. By then, about 60% of the world's population will be online.

    You're probably not going to give up your streaming services, but there are things you con do to help lessen the impact of your online use.

    Here are some tips:

    Disable autoplay(自动播放) for video on social media.

    Stream over Wi-Fi, not mobile networks.

    Watch on the smallest screen you can.

    Don't use high-definition(高清)video on devices.

    Computers are increasingly competing against humans to see whether man or the machine is more intelligent. In the latest show of artificial intelligence or AI, a computer went up against humans in live, public debates. The debates — held in San Francisco, June, 2018 — provided a new example of how computers are fast improving to think and sound more like humans.

    An AI system developed by major technology company IBM participated in the event. It is called Project Debater. IBM said it is the first time ever that an AI system has competed in a live, public debate with humans. Two separate debates were held between a computer and two human debaters.

    The company preselected possible subjects for discussion, but said neither the computer nor the humans knew the chosen subject before the debate. The discussions were set up in a similar way to most political debates. After preparing arguments, both sides got the chance to present a four-minute opening statement. Then came four-minute rebuttals(反驳), followed by closing statements.

    In one debate, IBM's computer battled Noa Ovadia, a former national debate champion. The AI system made a case in favor of the government subsidizing(补贴) space research. It pulled in evidence from its huge supply of information from newspapers, journals and other sources. Ovadia took the opposite position, arguing that the government could better serve the people by providing financial assistance to programs other than space exploration.

    Following closing statements from both sides, reporters and other attendees gave their opinions on the results. IBM reported that a majority of those who watched the debate said they believed Project Debater had improved their knowledge of the subject more than the human debater. On the other hand, the human debater got praise for better communicating her ideas.

A Housewarming Party

    A housewarming party is a special party to be held when someone buys or moves into a new apartment or house. The person or people who bought the apartment or house or moved are the ones who throw the party. It also gives people a chance to see what the new home looks like.  It is an opportunity to fill the new space with love and hopeful presents.

    It is traditional to bring a gift to a housewarming party. Some common items(物品) people will put on a gift registry include kitchen tools like knives and items like curtains. Even if there isn't a registry,  a good housewarming gift is something to decorate the new house with,  like,  a piece of art or a plant.  This is often appreciated since at a housewarming party there isn't a lot of food served, usually just appetizers or sandwiches.

     The host or hostess of the party will, however, probably give all the guests a tour of their new home. Sometimes, because a housewarming party happens shortly after a person moves into a new home, people may be asked to help unpack boxes. This isn't usual though.

    Housewarming parties get their name from the fact that a long time ago people would actually bring firewood to a new home as a gift so that the person could keep the home warm for the winter.

A. You can also bring food or drinks to share.

B. Different activities are held to make guests satisfied.

C. There are usually no planned activities at a housewarming party.

D. Now most homes substitute (替代) fires with central heating to keep warm.

E. Different people hold or attend housewarming parties for various reasons.

F. Some people register a list of things they would like to give as gifts at local stores.

G. The party is an opportunity for friends and family to congratulate the person or people on the new home.

    Not many 17-year-old girls know how to solder(焊)copper pipes together or clean the mess of plumbing(管道). These are1I've learned as an assistant to my2in his plumbing job.

    My summer job deals with messes that constantly arouse physical and mental 3, and the work demands an attitude of determination and 4that I frequently struggle to adopt.

    Each morning, I wrestle myself into large-thick men's jeans most girls would5to wear. I always6my hair back as I run out the door and climb into the passenger seat of the plumber truck. As my 7 begin babysitting, or selling groceries, my dad and I carry8toolboxes and work in the dark basements. I often become 9about looking for tools in messy storage boxes. Nothing around is beautiful or tidy.

    Sometimes I10why I stand the dust and sweat when I could be in my air-conditioned house doing summer homework. Yet as much as I11the mess of plumbing. I look down upon myself for being so easily annoyed by disorder.12, the world was built by people willing to get their hands13.

    Five such summers have14me that the messy parts of people's houses15the messy parts of their lives. As I learn to16the mess, I also learn to handle the17and the troubles in my adolescence. Life is a process of accepting18and learning to put it in order. Plumbing work is no different. And when customers express19I understand that, in a small way, we bring20to their lives.

    Li Ziqi, a young Chinese girl of the post-1990 generation,  become) a new online celebrity worldwide over the past few years. She started shooting short videos in 2016,  was inspired by the self-sufficient(自足的) lifestyle of ancient Chinese people. Most viewers found that the lifestyle and the picturesque landscapes in Li's videos enable them  (find) inner peace and give them a break from their stressful and busy urban routine. The spirit of struggling  independence and self-reliance conveyed by her life experience has attracted great attention at home and abroad. Nowadays she  (have) more than 18 million followers on Sina Weibo, and more than six million fans on YouTube. These numbers make Li  second most influential vlogger from China on international video-sharing platforms.

    Apart from showing how to cook, Li has even demonstrated other ancient  (skill), such as embroidery(刺绣), movable-type printing（活字印刷）, dyeing(染) cloth and making furniture. She has spent two years  (make) paper from tree bark, brushes out of rabbit hair, and other things with  (nature) materials. What's more, her house and clothing integrate into(融入) her traditional lifestyle  (perfect). Li says, “As an increasingly influential vlogger, I hope I can show the world the splendid cultural heritage of China.”

增加：在缺词处加一个漏字符号(ˆ), 并在其下面写出该加的词。

删除：把多余 词用斜线(\)划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意： 1．每处错误及其修改均仅限一词;

2．只允许修改10处，多者(从第11处起)不计分。

    Last week, I planned to pay a visit my grandparents. They were so exciting to hear the news because we have not seen each other for a long time. But my best friend invited I to take part in his birthday party and share his happy. When I thought of a promise that I had made it, I found it hard to make a decision. Eventually I chose to refusing my friend's invitation. Seeing my grandparents smile and the deliciously food they cooked for me, I knew 1 did something correct. We must keep our promise, and we will lose trust from others.

1）表示愿意；

2）介绍特产(茶、丝绸等);

3）询问要求(种类、数量、预算等)。

注意：1）词数100左右;

2)可以适当增加细节，以使行文连贯

3)开头和结尾已为你写好，但不计入总数。

参考词汇：特产 local special products  预算budget

Dear Jonah,

    I'm glad to know you are interested in Chinese local special products….……