As we know, DNA testing is very useful for crime fighting. But now crime fighters could have a new tool at hand. Researchers have developed a cutting-edge (前沿的) technique to identify human hair. Their test is quicker than DNA analysis techniques currently used by the police.

DNA testing is commonly used for identification because DNA is unique to each individual. However, environmental and chemical processes can degrade(降解) DNA, limiting its usefulness over time. Protein (蛋白質(zhì)) in hair, on the other hand, is more stable than DNA but can also have variations (變異體) that may be unique to the individual.

“Our analysis process can be used universally, ”says Ms. Huang, “One of our samples even included dyed hair and the test was 100 per cent accurate. The test was able to distinguish East Asians, Caucasians and South Asians.”

Dr. Beauchemin says she has got in touch with law enforcement agencies about using the new technology. She is also planning to collect more hair samples and continue her research with a goal of finding where exactly in the world hair sample is from, to look for more races and determine specific age.

“We are in a very similar place with protein-based identification to where DNA testing was during the early days of development,” said chemist Brad Hart. “This method will be a game-changer, and while we’ve made a lot of progress toward improving it, there are steps to go before this new technique is able to reach its full potential.”

1.What’s the main purpose of the text?

A. To analyze crime scenes.

B. To distinguish different races.

C. To show the usefulness of DNA testing.

D. To introduce a new identification method.

2.Which will be the most useful in identifying a person according to Brad Hart?

A. Chemical materials. B. Protein in hair.

C. DNA variations. D. Blood sample.

3.What’s the advantage of the protein-based identification over DNA testing?

A. Stability. B. Popularity.

C. Security. D. Convenience.

4.What can be inferred from the last paragraph of the text?

A. DNA testing will soon reach its full potential.

B. Protein-based identification remains to be improved.

C. Protein-based identification has replaced DNA testing.

D. DNA testing develops as rapidly as protein-based identification.

練習(xí)冊(cè)系列答案
相關(guān)習(xí)題

科目：高中英語(yǔ) 來(lái)源：遼寧省2017屆高三高考模擬測(cè)試英語(yǔ)試卷 題型：七選五

How to write a Letter to Parents

As a teacher, one of the most difficult parts of your job is working with parents. 1. Writing a letter to parents is one way to do this. If you do it properly, this is an excellent way to communicate when you cannot meet with parents face to face.

·Put positive communication in the letter, even if you are writing to discuss a problem. 2. Even if it is difficult, you must find this positive spin（言辭）, because it will make the parents more open to what you have to discuss. The general rule is “start with the good, hit them with the bad, then end on a positive note”.

·Share the problem with the parents. Express your concern and desire to help. 3. Show them through the letter that you want to work with them to find a solution to the problem.

·4. You can ask them to write back, sign a part of the letter or give you a call. If you do not hear from them, you should call them. Be caring, but make sure they got the communication. Remember, your goal is to work together to help their child succeed.

·Consider mailing the letter to the parent, rather than sending it home with the student. Some students will intentionally forget to give the letter to their parents, while others will accidentally or purposely lose the letter. 5.

A. Ask for a response.

B. Respect parents and never quarrel with them.

C. Whenever you meet with problems, you should keep cool.

D. Sending it in the mail makes it more certain that it will be received.

E. Do not place it completely on their shoulders, as they may hate this action.

F. You can do this by pointing out a little progress the child has made recently.

G. With proper communication, however, you can build bridges between the school and home.

查看答案和解析>>

科目：高中英語(yǔ) 來(lái)源：河北省卓越聯(lián)盟2016-2017學(xué)年高一下學(xué)期第三次月考英語(yǔ)試卷 題型：閱讀理解

With this letter I want to give up on my kitchen duties,until there is clear evidence of mutual respect（互相尊重）within the home.

For years it has been thought that I will be the one to pick up the dropped socks,turn off lights,turn on the dishwasher.But I reached my breaking point this weekend.Everyone was happy when the dog found a piece of bone. He played with it,carried it around and dropped it.You all watched,took photos,had fun and then went away.I was left finishing the lunch tidy-up,my heart warmed by all your laughter.

Until I came across the piece of fruit in some dog hair in the middle of the carpet.You had all seen it and walked away.Did anyone really want to pick it up?I don't mind walking the dog and bathing the cat.We have chosen to look after them.I'm building a family,a home filled with love.

But look at you now! My husband,with your job growing,each step forward,you have more challenges to conquer（戰(zhàn)勝）.My children,wonderful teenagers and young adults growing into yourselves,you are living your free lives.I love you all more than anything else in this world.But something went wrong—I became static（靜止的）.I became less the heart of the family,more the caretaker.

We are a family,a unit that lives and loves in a mutually supportive way.I'm inviting you to step up and join in. My position is open for discussion but never again will I play the role of cook and bottle washer.I will continue to cook at times—I love to do so—but only when I have the time.I have a life to live as well.

Your loving wife and mother

1.When the writer heard other members' laughter,she felt .

A. angry B. unequal

C. sad D. warm

2.According to the writer,how will the problem mentioned in this letter be solved?

A. She won't do the cooking at all.

B. She will act as the leader of the family.

C. She will find someone to do the housework.

D. Everyone will take his share to take care of the family.

3.To whom did the writer write this letter?

A. Her mother. B. Caretakers.

C. Her husband and children. D. Housewives.

4.Why did the writer write this letter?

A. To ask for respect from the family.

B. To offer housewives some suggestions.

C. To call on readers to help her.

D. To express her love to the family.

查看答案和解析>>

科目：高中英語(yǔ) 來(lái)源：廣西省桂林市2016-2017學(xué)年高二下學(xué)期期中考試英語(yǔ)試卷 題型：完形填空

My wife and I were attending a wedding at St. John’s Church. The sound of______rang to the heavens as the ceremony continued.

At the church, I______an old friend, Casper, who happened to be at the______. Now 73, Casper was a brilliant and______softball pitcher（投球手）back in the Men’s Leagues of Philadelphia in the mid-60s. I did not______the now silver-haired fellow until my brother-in-law John mentioned his name to me！After a very pleasant______, Casper asked if I remembered a letter of ______I had written to him back in 1964. It appeared Casper fell on hard times, as professional pitchers______do, and he wasn’t pitching too well for a period of time. I did not ______the letter, but he said, “Yes, I still have it and I read it anytime______aren’t going too well.” He said that he had read the letter many times, and the situation always seemed to improve. I was______and speechless!

He continued, “You don’t remember?” I said, “Sadly, no, I don’t.” But I did ask if I could have a(n)______of the letter. He said he would email it to me. After the______, we met on the steps of the church. Casper came up to me and______the letter. He lived a block from the______and had run home to get it. The envelope was______and turned yellow, and so was the letter inside. That letter had to be nearly 50 years old.

In______terms, the letter read:

“These hard times are______！Keep your enthusiasm for the______. Never quit and you’ll be back on the top again______. Hang on there!”

1.A. wind B. traffic C. music D. firework

2.A. took over B. ran into C. picked up D. called on

3.A. scene B. meeting C. service D. position

4.A. limited B. balanced C. devoted D. talented

5.A. recognize B. invite C. inform D. disturb

6.A. discussion B. shaking C. journey D. greeting

7.A. apology B. encouragement C. introduction D. appreciation

8.A. rarely B. entirely C. sometimes D. forever

9.A. receive B. write C. remember D. preserve

10.A. things B. stages C. effects D. jobs

11.A. pleased B. disappointed C. annoyed D. puzzled

12.A. address B. copy C. record D. opinion

13.A. break B. wedding C. party D. incident

14.A. opened B. delivered C. presented D. dropped

15.A. theatre B. church C. office D. station

16.A. faded B. painted C. folded D. divided

17.A. gentle B. patient C. modest D. simple

18.A. relative B. impressive C. temporary D. reasonable

19.A. game B. prize C. glory D. lesson

20.A. properly B. shortly C. totally D. casually

查看答案和解析>>

科目：高中英語(yǔ) 來(lái)源：福建省畢業(yè)班4月質(zhì)量檢查英語(yǔ)試卷 題型：短文改錯(cuò)

假定英語(yǔ)課上老師要求同桌之間交換修改作文，請(qǐng)你修改你同桌寫(xiě)的以下作文。文中共有10處語(yǔ)言錯(cuò)誤，每句中最多有兩處。每處錯(cuò)誤僅涉及一個(gè)單詞的增加、刪除或修改。

增加：在缺詞處加一個(gè)漏字符號(hào)（∧），并在此符號(hào)下面寫(xiě)出該加的詞。

刪除：把多余的詞用斜線(xiàn)（ \ ）劃掉。

修改：在錯(cuò)的詞下劃一橫線(xiàn)，并在該詞下面寫(xiě)出修改后的詞。

注意：1.每處錯(cuò)誤及其修改均僅限一詞；

2.只允許修改10處，多者（從第11處起）不計(jì)分。

Zhou Yan is the Senior Three student. Last week, he goes to see a doctor because of his arms and fingers hurt. The doctor told him the fact that had a “mobile phone disease”. Zhou sent messages for his friends with his mobile phone all the time, even in bed. Zhou started to do badly in all the exam because he spent so many time on his mobile phone. He didn’t stop use the mobile phone until his arms hurt. Yang Ling, which is an expert from a health center, said students should try to use their mobile phones less, especial at school.

查看答案和解析>>

科目：高中英語(yǔ) 來(lái)源：山東省濟(jì)寧市2016-2017學(xué)年高一下學(xué)期第二學(xué)段模擬考試英語(yǔ)試卷 題型：單詞拼寫(xiě)

1.Yesterday when I was w_______ on the pavement, I met an old neighbour.

昨天當(dāng)我徘徊在街頭時(shí)，我遇到了一位老鄰居。

2.P _______ me to lead the way, sir.

請(qǐng)?jiān)试S我來(lái)領(lǐng)路，先生。

3.Did you notice that man in r _______?

你注意到那個(gè)衣衫襤褸的人了嗎？

4.Eating too much is h _______ to health.

吃太多對(duì)健康有害。

5.We need an a _______ of hard-working in our class.

在我們班我們需要一種努力學(xué)習(xí)的氛圍。

查看答案和解析>>

科目：高中英語(yǔ) 來(lái)源：四川省2016-2017學(xué)年高二4月檢測(cè)考試英語(yǔ)試卷 題型：書(shū)面表達(dá)

假如你叫李華，你和父母在英國(guó)旅游期間于1月28日至30日入住Forest Hotel酒店，但對(duì)其提供的服務(wù)不滿(mǎn)意，請(qǐng)發(fā)電子郵件給酒店的管理者進(jìn)行投訴，要求其道歉并改進(jìn)服務(wù)質(zhì)量。

1.搬運(yùn)工送到房間的皮箱破損；

2.衛(wèi)生間漏水；

3.樓下酒吧有噪音，并持續(xù)到很晚，影響休息。

注意：

1.文章必須包括所有要點(diǎn)�？蛇m當(dāng)增加細(xì)節(jié)，以使文章連貫。

2.詞數(shù)120。

3.參考詞匯：搬運(yùn)工porter n; 皮箱suitcase n； 漏水leak vi.

________________________________________________________________________

查看答案和解析>>

科目：高中英語(yǔ) 來(lái)源：山東省棗莊市2016-2017學(xué)年高一下學(xué)期5月月考英語(yǔ)試卷 題型：閱讀理解

It was one of the hottest days of the dry season. We had not seen rain in almost a month. The crops were dying. Cows had stopped giving milk. The streams were long gone back into the earth. If we didn't see some rain soon we would lose everything.

I was in the kitchen making lunch for my husband and his brothers when I saw my six-year old son, Billy, walking toward the woods. He was obviously walking with a great effort... trying to be as still as possible. Minutes after he disappeared into the woods, he came running out again, toward the house.

Moments later, however, he was once again walking in that slow purposeful long step toward the woods. This activity went on for over an hour: walking very carefully to the woods, then running back to the house. Finally, my curiosity got the best of me. I quietly walked out of the house and followed him on his journey.

He was cupping both hands in front of him as he walked; being very careful not to spill(灑出) the water he held in them. Branches and thorns slapped his little face but he did not try to avoid them. He had a much greater purpose. As I looked at him secretly, I saw the most amazing site.

Several large deer appeared threatening in front of him. But Billy walked right up to them. I almost screamed for him to get away. And I saw a baby deer lying on the ground, obviously suffering from heavy loss of water and heat exhaustion, lift its head with great effort to lap up the water cupped in my beautiful boy's hand.

I stood on the edge of the woods watching the most beautiful heart I have ever known working so hard to save a life. As the tears that rolled down my face began to hit the ground, they were suddenly joined by other drops... and more drops... and more. I looked up at the sky. It was as if God, Himself, was crying with pride.

1.Why did the author follow her son?

A. Because there might be danger.

B. Because her son was doing a good deed.

C. Because she intended to help.

D. Because she was curious.

2.Which of the following statements is Not True according to the passage?

A. Rain was in great need.

B. Billy carried water with his small hands.

C. There were few trees in the woods.

D. Billy walked into the woods and then returned over and over again.

3.Which is the correct order of the development of the story?

① The author was moved to tears.

② Billy fed the water to the baby deer.

③ Billy walked towards the large deer.

④ It began to rain.

⑤ The author followed Billy into the woods.

A. ③②⑤①④ B. ⑤③②①④

C. ④①③②⑤ D. ⑤②①③④

4.Which of the following is the best title for the passage?

A. The water of life B. Importance of water

C. How to save animals D. Animals in danger

查看答案和解析>>

科目：高中英語(yǔ) 來(lái)源：河北省2016-2017學(xué)年高二下學(xué)期周練（5.21）英語(yǔ)試卷 題型：閱讀理解

Four books that will inspire you to travel the world

There’s truly nothing like travel when it comes to gaining perspective(遠(yuǎn)景) and exposing yourself to other cultures. To get you in the adventuring mood, we asked Amazon Senior Editor Chris Schlep to help us come up with a list of books that transport readers to another time and place. Below, see his list of four books that will inspire you to travel around the world. For more information, please click Amazon.com.

SEATTLE: Where You d Go, Bernadette

Price: $16.73

Maria Sample’s first novel is not exactly a love story to Seattle, but if you read it, you just might want to come here to see if people are really as self-involved as the characters in her book. What really shines through is the strange storytelling and the laughs. Buy it on Amazon.

ITALY: Beautiful Ruins

Price: $16.29

This book by the popular author Jess Walters is a love story that begins on the Italian Coast in the early 60s and eventually appears on the screen in Hollywood. With the settings of the background from Italy to Edinburgh to Los Angeles, you will find yourself longing to go as well. Buy it on Amazon.

ENGLAND: Wolf Hall

Price: $15.57

You can’t travel to Thomas Cromwell’s England without a time machine，but reading Hilary Mantel’s prize-winning novel is the next best thing. It will make you long to see the ancient buildings and green grass of the English countryside, much of which is still there. Buy it on Amazon.

NANTUCKET: Here’s to Us

Price: $ 17.16

Eli Hildebrand has built a writing career out of writing about her hometown island of Nantucket. Her latest is Here’s to Us, which, perhaps not surprisingly, is a great beach read.

1.Whose book has been made into a film according to the text?

A. Hilary Mantel’s.

B. Jess Walter’s.

C. Maria Semple’s.

D. Elin Hilderbrand’s.

2.What can you buy if you have only $32?

A. Beautiful Ruins and Where You’d Go, Bernadette.

B. Where You’d Go, Bernadette and Wolf Hall.

C. Beautiful Ruins and Wolf Hall.

D. Wolf Hall and Here’s to Us.

3.What do the four books have in common?

A. They have the same price.

B. They have the similar content.

C. They have the similar background.

D. They have the same place of sales.

4.Where does the text probably come from?

A. A website.

B. A magazine.

C. A newspaper.

D. A textbook.

查看答案和解析>>

同步練習(xí)冊(cè)答案