Since December,there have been tens of thousands of the COVID-19 cases both in and out of China,caused by a previously unknown virus:novel coronavirus.
What are they?Viruses are considered to be non-living organisms(有机物).They can't reproduce(繁殖) on their own. Instead, they invaded the cells of living organisms to reproduce, spread and take over.But the basic question is,where did viruses first come from? Until now, no clear explanation for their origin exists.
Understanding the origins of viruses means fully understanding the history of their hosts not only humans,but also bacteria,plants and other animals,which is a complicated task. However,there are three main theories to explain the origin of viruses.First,viruses started as independent organisms,then became parasites(寄生者). Second,viruses evolved(进化) from pieces of DNA or RNA that"escaped"from larger organisms.The third one is that viruses co-evolved with their host cells,which means they existed alongside these cells.
For the time being,these are only theories.The technology and proofs we have today cannot be used to test these theories and discover the most plausible explanation.Continuing studies may provide us with clearer answers.Or future studies may find that the answer is even more mysterious than it now appears.
1.What can we learn about viruses from the article?
A.They mainly infect animals and plants.
B.They are really small living organisms.
C.They are more dangerous than bacteria.
D.They can't reproduce unless they find a host cell.
2.Which of the following might explain the origin of viruses?
A.They evolved along with their host cells.
B.They evolved from the DNA or RNA in animals.
C.They evolved from the fossils of large organisms.
D.They evolved from parasites to independent organisms.
3.The underlined word"plausible"in the last paragraph probably means______.
A.creative B.reasonable
C.common D.unbelievable
4.What can we conclude from the article?
A.The author is confident about future virus research.
B.Viruses will become more like bacteria as they evolve.
C.Viruses live longer in human host cells than in animals.
D.It may take a long time to understand the origin of viruses.
One summer night, the whole family of Irene was asleep with the windows open. It was very quiet when there was a loud noise from the stable(马厩）.Irene woke up from her sweet dream,and the noise continued.Then she heard a horse running fast towards the house.The next thing she saw was her horse,Thunder,standing outside of her window,neighing(嘶叫） and shaking his head.She knew something was wrong.Irene quickly got everyone out of the house before the earthquake hit.Thunder saved her life.
As amazing as this story is,it is not as uncommon as you may hear of the story of Doris and her cat Maggie.One night,Doris was in a deep sleep when she was woken by her cat Maggie.Maggie was meowing wildly outside Doris's bedroom and throwing herself against the closed bedroom door.When Doris opened her eyes,she saw her bedroom full of smoke.As she escaped her house,she saw a fire was burning in her kitchen.Even though Maggie could have escaped the house through a cat door,she wouldn't leave Doris.
There are also stories of wild animals coming to the rescue of humans.Once,Lyndon was surfing with his friend when he was attacked by a four-meter shark.During the attack,a group of dolphins came to his rescue by forming protective ring around Lyndon until be could get safely to shore.Without the help of the dolphins,there is little chance that Lyndon could have escaped.
No one is sure why animals have so often come to our rescue.However,it is clear that most of us haven't realized their kindness.It is important that we care for them as much as we can.
1.What was Irene doing before the earthquake hit?
A.She was sleeping soundly.
B.She was opening the windows.
C.She was visiting her neighbors.
D.She was getting her horse out of the stable.
2.Why did Maggie throw herself against the door?
A.She was afraid of smoke.
B.She wanted to get out of the room.
C.She was trying to wake up her owner.
D.She felt bored and was playing by herself.
3.What do we know about Maggie and Thunder?
A.They were shy and quiet.
B.They were brave and devoted.
C.They often made noise at night.
D.They saved their owners some times.
4.What can we know from the article?
A.It is clear why animals often save humans.
B.Humans haven't realized animals' s kindness
C.Humans have a good relationship with animals.
D.Animals can often come to the rescue of humans.
A Guide to the University
Food
The TWU Cafeteria is open 7a.m.to 8p.m..It serves snacks,drinks,ice cream bars and meals.You can pay with cash or your ID cards.You can add meal money to your ID cards at the Front Desk.Even if you do not buy your food in the cafeteria,you can use the tables to eat your lunch,to have meetings and to study.
If you are on campus in the evening or late at night,you can buy snacks,fast food,and drinks in the Lower Cafe located in the bottom level of the Douglas Centre.This area is often used for entertainment such s concerts,games or TV watching.
Relaxation
The Globe,located in the bottom level of McMillan Hall,is available for relaxing,studying, cooking,and eating.Monthly activities are held here for all international students.Hours are 10 a.m.to 10 p.m.,closed on Sundays.
Health
Located on the top floor of Douglas Hall,the Wellness Centre is committed to(致力于）physical,emotional and social health.A doctor and nurse is available if you have health questions or need immediate medical help or personal advice.The cost of this is included in your medical insurance.Hours are Monday to Friday,9:00 a.m.to noon and 1:00 to 4:50 p.m..
Academic Support
All students have access to the Writing Centre on the upper floor of Douglas Hall.Here, qualified volunteers will work with you on written work,grammar,vocabulary,and other academic skills.This service is free.
1.What can you do in the TWU Cafeteria?
A.Do homework and watch TV.
B.Buy drinks and enjoy concerts.
C.Have meals and meet with friends.
D.Add money to your ID and play chess.
2.Where and when can you cook your own food?
A.The Globe,Friday.
B.The Lower Cafe,Sunday.
C.The TWU Cafeteria,Friday.
D.The McMillan Hall,Sunday.
3.The Guide tells us that the Wellness Centre______.
A.is open six days a week
B.offers services free of charge
C.trains students in medical care
D.gives advice on mental health
假定你是李华，你市将举办留学生汉语演讲比赛，主题为“我眼中的中国”(China in my eyes)。请给在你校留学的Jonah写一封电子邮件。内容包括：
1. 演讲主题；
2. 比赛时间和地点；
3. 邀请他代表你校参加。
注意：1. 词数80左右；
2. 可适当增加细节，以使行文连贯。
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假定英语课上老师要求同桌之间交换修改作文,请你修改你同桌写的以下作文。 文中共有10处语言错误,每句中最多有两处。每处错误仅涉及一个单词的增加、删除 或修改。
增加:在缺词处加一个漏字符号（∧ ），并在其下面写出该加的词。
删除:把多余的词用斜线（\）划掉。
修改:在错的词下画一横线，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。
Patsy Smith has raised ducks for many years. One of her ducks, Peg, losing one of his legs from a fight with a tortoise. Mrs. Smith calls for help to see if anyone could create new leg for Peg. Three students thought they would probable use their 3D printer to create a leg for him! They spent several months creating and testing different model. It turned out to be a lot more difficult than they had thought! Luckily, their hard work was paid off and they created a model who fitted Peg's leg perfectly! Now, Peg can walk or even run just like her duck partners! And Mrs. Smith is very thankful for them.
阅读下面短文，在空白处填入1个适当单词或括号内单词的正确形式。
Coronaviruses(冠状病毒)are a large family of viruses that cause disease in mammals and birds. Coronaviruses can cause illnesses that range 1. the common cold to many more severe illnesses.
The 2. (new)identified virus，called COVID-19，is thought to have spread to humans from wild animals sold at a market in Wuhan，in 3.(centre)China’s Hubei Province. But it is now spreading between people. Chinese officials say 4. disease is able to spread from one person to another even before any actual signs appear，5. makes it especially hard to contain.
Signs of some patients 6. (affect)by the disease have included fever，cough，shortness of breath and general breathing difficulities. In some more severe 7. (case)，the virus can cause pneumonia(肺炎). Some people report few or no signs，while others have gotten very sick or even died. There is no special 8.(treat)for the new coronavirus at present. However，many of its effects are treatable，as long as a patient is in fair health.
Last week the US Centers for Disease Control also 9. (publish)prevention tips. It says：wash your hands for at least 20 seconds with soap and water；avoid 10. (touch)your face with unwashed hands；stay home when you are sick；clean objects and surfaces that are touched often.
