Blue light before bedtime can make it harder to sleep, and the screens on phones, computers, and televisions send out plenty of blue light. This is all true. But if you're focused on blue light as a major problem affecting your sleep or your eye health, it's time to look at it from another aspect.
As Philip Yuhas, a professor of vision, writes at The Conversation, blue light isn’t a uniquely technological evil. It's part of sunlight, and your eyes are exposed to plenty of it all the time. You ' re fine. There are studies in mice that have found blue light can damage their eyes, but mice are nocturnal creatures (夜行动物) whose eyes are different from ours. The pigments (色素) and the lenses (晶状体) of our eyes actually block blue light fairly well--so in a sense, we already have built-in blue blocking protection
Adding more protection isn't likely to help though. You can buy glasses and screen filters (滤光片) that block blue light, but Yuhas points out they are probably a waste of money: these products do not block out much blue light. The leading blue-blocking anti-reflective coating, for example, blocks only about 15% of the blue light that screens send out. You could get the same reduction just by holding your phone another inch from your face.
The American Academy of Ophthalmology doesn't recommend blue-blocking products, either. Instead if you're concerned about your eye health or your ability to get to sleep on time, you already know what to do:
Put the screens away at bedtime. Read a book or find something else to do. While you're using screens take a 20-second break every 20 minutes to look at something 20 feet away ( the "20-20-20 " rule ). If you get dry eyes when you look at screens for a long time, use eyedrops labeled artificial tears.
1.What do people think of blue light generally?
A.It is a necessary part of sunlight. B.It is magical and rare.
C.It is the major factor affecting sleep. D.All electronics send out blue light.
2.What did the studies in mice find?
A.Mice can see clearly in the dark. B.Our eyes actually block blue light well.
C.Eyes can be long exposed to blue light. D.Blue light can damage mice's eyesight.
3.What can we know about blue-blocking products?
A.They block only 15% of the blue light. B.Few have much effect on the blue light.
C.They can prevent much harmful lights. D.They are thought highly of by experts.
4.What could be the best title for the text?
A.How can Blue Light Be Prevented? B.Why does Blue Light Make Sleeping Hard?
C.Are Blue-blocking Products Necessary? D.What will Blue Light Affect Actually?
Although the size of the overall new vehicle market is larger than it was a decade ago, the size of Canada's midsize car market has been fallen to half. With figures in October, 2019 from Global Automakers of Canada look at their current state.
Ford Fusion: 7 280 sales, up 16 percent
Fusion sales reduced 15 percent in 2015, 9 percent in 2016,33 percent in 2017 and 27 percent in 2018. As Ford clears out the departing Fusion in 2019, sales are rising. Between the Fusion's 20 145-unit peak in2013 and 2018, the former best-seller took a 65-percent dive.
Toyota Camry: 11 579 sales, up 4 percent
When the Camry took over from the Ford Fusion as Canada's top-selling midsize car in 2012, the Camry's market share was little more than half as strong as it is now. Yet while Toyota sold 18 203 Camrys that year (far from the 28 218 that were sold five years earlier). Toyota will find 15 000 buyers in 2019, with a little help from the daily rental market.
Honda Accord: 9 089 sales, down 13 percent
The Accord is, by modern standards, a popular midsize car. But this 10th-generation car is a far cry from the Accord that led the market with 25 814 sales in 2004. Honda is not likely to sell half so many Accords in Canada in 2019, although the car's market share has grown from the 13 percent it held in 2010
Chevrolet Malibu: 4 674 sales, down 14 percent
The Malibu had continuous improvements in 2013, 2014, 2015 and 2016. But after reporting 11 503 Malibu sales in 2016, GM Canada sold 29 per cent fewer in 2017 and then posted an 18-percent Malibu drop in 2018. Demand is weakening further in 2019.
1.Which car has the biggest rate of change in 2019?
A.Ford Fusion. B.Toyota Camry.
C.Honda Accord. D.Chevrolet Malibu.
2.What helps Toyota Camry sell the most cars?
A.Its strong structure. B.Its popular midsize.
C.The most market share. D.The flexible market policy.
3.What do the four cars have in common?
A.Sales are not optimistic in 2019. B.Sales trends are not what they used to be.
C.New generations will improve car sales. D.These data are from all over the world.
假如你是李华,你的美国朋友 Peter对中国的书法(Chinese calligraphy)很感兴趣,2019年10月10日下午2:30在国家艺术博物馆举行中国书法优秀作品展的开幕式。请你根据以下提示用英语给 Peter写一封电子邮件,并邀请他一起参加开幕式和观展。
提示如下:
1.提出要求;
2. 简述原因;
3.请求答复。
注意:1.词数100左右;
2.可根据内容要点适当增加细节,以使行文连贯。
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假定英语课上老帅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。
Dear Eden,
I'm awful sorry that I have to ask a favor for you in the hope that you can be kind to help me.As you know it,I'm apply for a part-time job.In addition,I have to pass a oral test.However my speaking English is very poor.Otherwise,I hope you will give me some advice on how to speak better and that I can practice it with you together.I had promised to be a diligent student.If you are available,please call me as soon as possible.I hope that I can visit you in the following two day.I would appreciate very much if you could help me.I'm looking forward to your early reply.
Yours,
Dave
阅读下面短文,在空白处填人1个适当的单词或括号内单词的正确形式。
The world's last and loneliest surviving male northern white rhino,Sudan,has died.He was 45 and lived in Kenya.
His1.(die)means there are only two rhinos of this type 2. (leave)alive in the entire world.They are both female-and are Sudan's daughter and granddaughter.
Rhinos are the second 3.(large)land mammal after elephants.There are around 20 thousand southern white rhinos living in the wild.But the northern white rhino4.(endanger)-with just two left now.
5.Sudan has died is a cruel symbol of humans' ignoring nature.Because of hunting,white rhinos were almost wiped out in the 1970s and 1980s.
But 6.so many other wildlife species on Earth,why is the white rhino so important?The answer is down to biodiversity.Scientists say that all species are interconnected.They depend on one another.With less biodiversity,these 7.(connect)weaken and sometimes break,8.(harm)all the species in the ecosystem.
Is there any hope for the species in the future? 9. (Fortunate),efforts are being made to save the white rhino.Scientists now hope they may be able to use10.special technique called IVF to try to help save the species.Before Sudan died,some of his genetic material was taken and carefully stored.Scientists hope that the two females can have their own children one day.
I was the fourth generation to live on a land of woods and fields that had once been a working farm.Through the___,my family watched a city spread all around us. Gradually, neighboring families sold their houses,which were____with housing developments and____centers.
When I was a student in college,a shopping center was built directly behind us.While it was now ___to do our shopping,we also had to get used to the ___noises at night from delivery trucks.
One morning,having finished my exams for the last term,my mother and I walked on the land while talking about my future plans.Megan,our three-year-old dog,had____into the woods.Before long Megan reappeared,carrying some____in his mouth.My mother had always been proud of teaching her children good___ .It was clear by the look on her face that she had the same___ of the dog.
She looked____at the possibility that the dog could be a criminal.Maybe somebody had thrown it into the trash and Megan had simply____it up.Mum kept a watchful eye on him to ____that it did not happen again.For a while things seemed____However,one Saturday afternoon my mother sent me to the store to get some last-minute things.
While at the checkout counter I heard the___ worker say,"Oh here comes that dog again. I watched,__,as everyone laughed.He __ to the bread shelf,took some bread and walked out.All I could think of to do was to offer to___ for the bread.When I got outside,the dog was___ in sight.I found him at home with the bread and told Mum what I had just seen.My mother took the bread from the dog and shook her head in___.She could not believe she had____a shoplifter.
Megan was locked inside the house after that.
1.A.farms B.generations C.woods, D.families
2.A.destroyed B.bought C.designed D.replaced
3.A.conference B.game C.shopping D.culture
4.A.important B.necessary C.convenient D.difficult
5.A.loud B.weak C.amazing D.rare
6.A.barked B.looked C.pointed D.disappeared
7.A.meat B.bread C.chocolate D.waste
8.A.values B.skills C.songs D.knowledge
9.A.disappointment B.sympathy C.disagreement D.expectation
10.A.interested B.frightened C.tired D.pleased
11.A.picked B.given C.turned D.kept
12.A.stick out B.break up C.make sure D.think about
13.A.funny B.simple C.ordinary D.good
14.A.woods B.store C.house D.college
15.A.ashamed B.happy, C.helpless D.careless
16.A.left B.knocked C.headed D.threw
17.A.run B.ask C.stand D.pay
18.A.somewhere B.nowhere C.anywhere D.everywhere
19.A.disbelief B.encouragement C.trouble D.demanding
20.A.lost B.known C.raised D.sent