Radar（雷达） is an electronic device that detects planes, ships, coastlines, landmarks, and even storm clouds. The name radar comes from the first letters of the words radio direction and ranging. As the human eye uses light waves to see, radar “sees” with radio waves. Without radar, planes could not land safely in bad weather and ships could not move safely in thick fog.1.
In the 1800s it was discovered that radio waves could be reflected from objects. But scientists did not make great advances in radar research until the 1930s, when the world was threatened by war.2. It has been used widely in almost every conflict since then.
Echoes make it possible for radar to work. When a beam of radio waves is sent out, it strikes on an object and returns an echo. This echo is picked up by radar and recorded on a screen similar to television screen. On the screen an observer sees a flash, or a blip, that shows the direction and distance of the object.3.
Airport control towers use radar to guide planes in for safe landings. Almost all large ships depend on radar to prevent collisions with icebergs or other ships. 4.Weather forecasters “see” the size, direction, and speed of storms on radar screens. Astronomers can even use radar to measure accurately the distance to the moon. Thus, the device has generated major advancements.
5. Huge radar antennas have been installed all over the United States. They guard us against possible enemy attacks. We have ballistic—missiles (战略导弹)warning systems that can alert us to attacks when missiles are more than 1,000 miles away. Other radar systems warn us against enemy aircraft and even spying space satellites.
A. Police track speeders in radar-equipped cars.
B. These measurements are now highly accurate.
C. The device can be used in a wide range of fields.
D. During World War II many countries used radar effectively.
E. It is therefore especially valuable to shippers and travelers.
F. Today radar is used by commercial airliners and weather forecasters.
G. Strengthening national defense is one of radar’s most important functions.
Sea turtles are one of several species that have temperature-dependent sex determination. The number of female babies increases when nests are made in warmer sands.
A recent study by the National Oceanic and Atmospheric Administration, California State University and Worldwide Fund for Nature Australia examined two genetically distinct populations of green sea turtles living in the Great Barrier Reef. The study found that a group of about 200,000 turtles living in the northern part of the reef was almost entirely female.
While the southern population was 65 to 69 percent female, females in the northern group accounted for 99.1 percent of young turtles and 86.8 percent of adults.
After combining their results with temperature data, the scientists in charge of the study found that the northern green turtles have been producing mainly females for more than two decades and that the complete feminization(雌性化) of this population is possible in the near future.
The temperature at which the turtles will produce male or female babies can be passed on to the turtles' children. Most sea turtle populations are now producing offspring above the most suitable temperature, making it clear that climate change causes a serious threat to the survival of these populations.
The chief executive Of World Wildlife Fund Australia, Dermot O'Gorman, said this is another sign of the impact of climate change, following recent research that shows that coral bleaching (珊瑚白化) events are occurring far more frequently than in the past.
“We've had two years where we've had mass bleaching events on the Great Barrier Reef,” he told Guardian Australia. “That's a very visible sign of the impact of climate change. But this is a quiet change. We can't see the impact it's having on a turtle population until a study like this shows some long-term trends.”
The lead author of the paper, Dr Michael Jensen, said the findings represent a major environmental conservation issue.
O'Gorman said more urgent action on climate change is clearly needed, adding that some conservationists have already taken practical measures, such as using shade cloth on turtle nesting beaches to lower the sand temperature, and reducing bycatch(误捕) in the fishing industry.
"Shade cloth can be used in certain places, but there's a limit to the scale you can do that, " he said. "Now every large male who can reproduce is going to be even more important.
1.According to the research on Great Barrier Reef's green sea turtles, __________.
A.about 65 to 69 percent of northern turtles are female
B.86.8 percent of southern turtles have grown up to adults
C.the feminization of green sea turtles could become worse
D.adult green Sea turtles can change their sex in warmer places
2.Why did O'Gorman mention coral bleaching?
A.To suggest that climate change poses more risks to coral than turtles.
B.To compare the living environments of turtles and coral.
C.To urge people to take practical measures to fight climate change.
D.To stress this discovery about green sea turtles is very valuable.
3.Conservationists are taking action to __________.
A.keep the sea turtles' nests cool
B.stop the illegal fishing of green sea turtles
C.expand the size of the green sea turtles' nesting places
D.build special nests for turtles to produce offspring
4.Which would be the best title for the article?
A.How climate change affects ocean creatures
B.Invisible change caused by global warming exposed
C.Necessity of protecting green sea turtles and their habitat
D.Global green sea turtle populations in greater danger
Aging happens to all of us, and is generally thought as a natural part of life. It would seem silly to call such a thing a “disease”.
On the other hand, scientists are increasingly learning that aging and biological age are two different things, and that the former is a key risk factor for conditions such as heart disease, cancer and many more. In that light, aging itself might be seen as something treatable, the way you would treat high blood pressure or a vitamin deficiency.
Biophysicist Alex Zhavoronkov believes that aging should be considered a disease. He said that describing aging as a disease creates encouragement to develop treatments.
“It unties the hands of the pharmaceutical(制药的) industry so that they can begin treating the disease and not just the side effects,” he said.
“Right now, people think of aging as natural and something you can't control.” he said. “In academic circles, people take aging research as just an interest area where they can try to develop interferences. The medical community also takes aging for granted, and can do nothing about it except keep people within a certain health range. ”
But if aging were recognized as a disease, he said, “It would attract funding and change the way we do health care. What matters is understanding that aging is curable.”
“It was always known that the body accumulates damage” he added. “The only way to cure aging is to find ways to repair that damage. I think of it as preventive medicine for age-related conditions. ”
Leonard Hayflick, a professor at the University of California, San Francisco, said the idea that aging can be cured implies the human lifespan can be increased, which some researchers suggest is possible. Hayflick is not among them.
“There're many people who recover from cancer, stroke, or heart disease. But they continue to age, because aging is separate from their disease,” Hayflick said. “Even if those causes of death were removed, life expectancy would still not go much beyond 92 years.”
1.What do people generally believe about aging?
A.It should cause no alarm whatever the circumstances.
B.It should be regarded as a kind of disease.
C.They just cannot do anything about it.
D.They can delay it with advances in science.
2.How do many scientists view aging now?
A.It might be prevented and treated.
B.It can be as risky as heart disease.
C.It results from a vitamin deficiency.
D.It is an irreversible(不可逆转的) biological process.
3.What do we learn about the medical community?
A.They now have a strong interest in research on aging.
B.They differ from the academic circles in their view on aging.
C.They have ways to prevent people's aging process.
D.They can contribute to people's health only to a limited extent.
4.What does Professor Leonard Hayflick believe?
A.Aging is hardly separate from disease.
B.The human lifespan cannot be lengthened.
C.Few people live up to the age of 92.
D.Heart disease is the major cause of aging.
"I didn't hear them call my name," explained Shelley Hennig to Active Teens (AT) as she talked about that exciting moment on national television when she won the honor of Miss Teen USA 2004. "Are you ready?" is what she heard. Then she said, "I shook my head no, and then they said ‘yes’ and it was announced again."
It was four days after that life changing moment for the seventeen-year-old high school student from Destrehan, Louisiana----she was still______．
"I was so shocked! I never believed that it could actually really happen." Present in the audience（观众）that day were: her mother and father, older brother, her friends, and her dance teacher.
Understanding why members of her family and her friends would be there, AT asked why her
dance teacher had traveled so far to see her compete（比赛）．"She's always been my role model．I've danced with her since I was six. She's been through so many difficulties and came through them all. I've learned to get over bad life's experiences and learned how to move on because of her."
One of those bad life's experiences for Shelley happened three years ago when her brother Brad was killed in a drunk driving accident. He was 18. She found writing helped her get through the rough days. She said, "I write a lot about my brother. I write a lot, a lot, a lot...”
As Miss Louisiana Teen, she traveled around the state speaking to teens（青少年）about the dangers of drinking and driving. In her role as Miss Teen USA, Sheiley will continue to speak to youth about safe driving, in addition to many other things to help the youth.
When AT asked Miss Teen USA if she had any advice for our readers, she said, "Don't let anyone change you. Hang out with people that make you feel good about yourself. That way, it is easy to be yourself."
1.What do the words “on cloud nine” in Paragraph 2 probably mean?
A.frightened B.troubled C.very happy D.very angry
2.Shelley takes her dance teachers as a role medel mainly because she is .
A.determined B.friendly C.strict D.experienced
3.How many children did the Hennigs have according to the text?
A.1. B.2. C.3. D.4.
4.What suggestion does Shelley give to the teens?
A.Be yourself with the support of friends
B.Meet friends whenever possible
C.Go easy on yourself and others
D.Have a good role model
WELCOME TO THE VIRTUAL REALITY CINEMA AMSTERDAM
World's First Reality Cinema
Going to the VR CINEMA offers you the opportunity to watch movies like you've never done before. You can see 360 degree movies using a VR headset. In the VR CINEMA, ringing mobile phones and noisy visitors belong to the past. Furthermore, traditional red cinema chairs or the big white screen are nowhere to be found. Instead, a Samsung Galaxy S6 (smart phone) together with the Samsung Gear VR (virtual reality glasses) transports you to a wholly new world. Headphones shut out background noise, and above all, offer super sound quality. Turning chairs allow you to freely look around and see what's happening above, below, behind, in front, on the right and on the left side of you. So no sore neck, we promise.
In the VR CINEMA, you will experience 30 minutes of the coolest virtual reality films. We proudly present four film selections in different themes in order to please every virtual reality lover. Are you brave enough for our scary films? Will you lose yourself in VR documentaries from around the globe? Do you prefer to go on an adventurous journey like no other? Or do your kids want to swim with dolphins, interact with magical characters, and experience the moving stories beyond imagination? Supernatural, Documentary, Journey and Fun are waiting for you!
For kids, young and older ones, there's the cheerful and colorful selection. The only thing you have to do is sit back, relax and enjoy the VR experience of your choice.
Location: Oosterdokskade 5, 1011 AD Amsterdam The Netherlands
Tel: +31(0) 627006916
E-mail: mail@thevrcinema.com
Ticket Price: ￡12.5
Opening hours: Wednesday, Thursday & Friday: 14:00-21:00
Saturday & Sunday: 12:00-22:00
1.What is the VR CINEMA like?
A.It has a big white screen. B.It is full of noisy visitors.
C.It is quipped with red chairs. D.It offers 360 degree movies.
2.What can you do in the VR CINEMA?
A.Join the swimming club.
B.Experience the touching unimaginable stories.
C.Act as magical characters.
D.Lose yourself in VR documentaries only from America.
3.What’s the main purpose of the text?
A.To introduce new VR films. B.To present VR film schedules.
C.To report development of VR films. D.To attract people to the VR CINEMA.
假定你叫李华，是红星中学的学生。你的老师给你介绍一位美国笔友Tom, 请用英文给他写一封邮件，介绍你的校园生活。内容必须包括：
1. 自我介绍（姓名、年龄、学校）；
2. 学习情况（介绍最喜欢的一门科目）；
3. 课余活动（如体育或艺术活动）。
注意：1. 词数100左右，不允许出现真实的姓名和地名；
2. 邮件的开头和结尾已经给出，不计入总词数；
3. 可适当增加细节，以使行文连贯。
Dear Tom,
It’s nice to make friends with you.
_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
I’m looking forward to your reply.
Yours sincerely,
Li Hua
