If we are driving a car or crossing a street, we will stop when the traffic lights turn red. Why do we use red rather than other colors?
As we know, scattering (散射) happens when light goes through the air. For the same media, if the wavelength (波長(zhǎng)) is long, the scattering will be short. If the wavelength is short, then the scattering will be long.
Of all light we can see red has the longest wavelength, so the scattering is the weakest. That means the red light travels far. In fact, it travels farther on rainy days.
Using the red light can help drivers in farther areas see the lights. It helps drivers slow down or stop in time. If drivers don’t see the red light until they are close, they may not be able to stop the car in time. An accident may happen. Red can also excite people. We can act more quickly when we see the color red.
In a word, red light helps drivers stop in time and help prevent accidents.
小題1:______ has the longest wavelength of all light we can see.
A．RedB．GreenC．YellowD．Black
小題2:Red light travels farther on ______ days.
A．windyB．sunnyC．rainyD．cloudy
小題3:Red can make people act more quickly because ____________.
A．red can make people happierB．the scattering of red is very short
C．the scattering of red is very longD．red can make people more excited
小題4:The underlined word “prevent” means ______ in Chinese.
A．逃避B．防止C．處理D．檢查
小題5:The passage mainly tells us ____________.
A．why accidents happenB．how the red light travels
C．why we use red traffic lightsD．how to stop in time at traffic lights

小題1:A
小題1:C
小題1:D
小題1:B
小題1:C

小題1:根據(jù)we can see red has the longest wavelength,描述可知選A。
小題1:根據(jù)In fact, it travels farther on rainy days. 可知選C。
小題1:根據(jù)Red can also excite people. We can act more quickly when we see the color red. 可知選D。
小題1:根據(jù)上文stop in time 及時(shí)停止，可知下文句意為預(yù)防阻止事故，故選B。
小題1:通過短文描述可知本文主要是介紹了人們?yōu)槭裁词褂眉t色作為交通信號(hào)燈，故選C。
練習(xí)冊(cè)系列答案
相關(guān)習(xí)題

科目：初中英語(yǔ) 來源：不詳 題型：閱讀理解


Canberra is the capital of Australia. It is a modern and lively city with a population of over 345 000.
 
History
Canberra is the eighth largest city in Australia.
It is 238 km from Sydney and 507 km from Melbourne. Melbourne was once the capital of Australia. Sydney people also wanted to make their city the capital. It was difficult for the government to make the decision. Then in 1911, the government chose a place to build the new capital. It was between Sydney and Melbourne, the two largest cities in Australia. It took more than 14 years to build the city. In 1927, the city was set up. It became the capital and was named Canberra. “ Canberra” means “a place for friends to get together”.
                         Culture
Canberra is a beautiful city with trees and flowers everywhere. There’s a Flower Festival in September each year. People can enjoy all kinds of beautiful flowers and welcome the spring to arrive. A man-made lake --- Lake Burley Griffin is in the center of the city. It’s about 25 km long. People like to ride bikes, walk or run around the lake. In Canberra, there’re many famous universities like the Australian National University and the University of Canberra. The National Library and the National Museum of Australia are also famous places that people like to visit.
小題1:How far is Canberra from Sydney ?
A．25 km.B．238 km.C．345km.D．507 km.
小題2:The word “ Canberra” means ____________.
A．the largest cityB．a(chǎn) beautiful man-made lake
C．the old capital cityD．a(chǎn) place for friends to get together
小題3:Canberra Flower Festival is a festival to ____________.
A．ride bikesB．visit universities
C．welcome the springD．walk around the lake

查看答案和解析>>

科目：初中英語(yǔ) 來源：不詳 題型：閱讀理解


Top help you decide what might make a good pet ,we’ve put together a pet checklist .We’ve named some of the animals that are often kept as pets .We’ve shown some good points and bad points about each .And we hope it may help you make the best choice（選擇）
Pick-a-Pet Checklist（清單）
Pets
Good Points
Bad points
Rabbit
Easy to keep
Enjoy being petted
Good to hold
Hard to house train
Drop lots of hair
Easily upset by high temperature
Raccoon
Can be very interesting
Can be friendly when young
Against the law to keep in many states in the U.S.
Can get unkind when older
Cat
Easy to feed & care for
Can live indoors or out
Fun to hold
Very friendly
May scratch furniture
Little pans can be messy
May kill birds
May make you sneeze
Dog
Come in many sizes
Can live indoors or out
Fun to love & play with
Very friendly
Can give safety
Can be smelly ,messy ,noisy
Need to be licensed& trained
May make you sneeze
May bite(咬)if angry
Need lots of attention
小題1:You are ______ to keep a raccoon as a pet in many places of America.
A. suggested  B. encouraged  C. not allowed
小題2:It would be easier for you to keep a ______ as a pet if you’re often too busy to take care of it .
A. rabbit or raccoon  B. rabbit or cat  C. raccoon or dog
小題3:If you feed birds at home , you should be very careful to choose a ______ as your another pet.
A .rabbit  B. raccoon  C. cat
小題4:The dog may ______ you if you make it angry .
A. hurt  B. fix  C. train
小題5:The writer tries to help us______ with the checklist .
A. learn how to look after our pets
B. find which animal is our best choice as a pet
C. Know what kind of animals can be kept as a pet

查看答案和解析>>

科目：初中英語(yǔ) 來源：不詳 題型：閱讀理解

There are many ways to find a job. It can be as easy as walking into a neighborhood store to look at its announcement(通告) board. Local stores often have areas where people can put small signs telling what kind of service they need or can provide. Such services include caring for children or cleaning houses.
Or, job searchers can look in the newspaper. Local newspapers have employment announcements placed by companies seeking(尋找) workers.
Another popular tool for finding jobs is the Internet. For example, people in four hundred and fifty cities around the world can use the Craigslist(網(wǎng)站名)Web site to buy objects, meet people or find a job. Craigslist says that it receives two million new job listings each month.
Another useful way to find a job is through a college or university. For example, students at the University of Texas in Austin（奧斯丁 (美國(guó)得克薩斯州首府)） can go to the Career Exploration Center to get help in finding a job. Of course, looking for a job requires knowing what kind of work you want to do. For example, there is a book called “What Color is Your Parachute (降落傘)?” by Richard Bolles. This book has been helping people choose a career (職業(yè)) since it was first published in nineteen seventy.
Some experts(專家) also help people find jobs. Susan W. Miller owns a company called California Career Services in Los Angeles. She says her company helps people find jobs by first helping them understand their strengths, goals and interests. Then she provides them with methods and resources(對(duì)策) to help them find the right job.
小題1:What is the passage mainly about?
A．Finding a job.
B．College students’ part-time jobs.
C．Craigslist Web site.
D．The relation between study and work.
小題2:It can be learned from the passage that ______.
A．companies often put job information in local shops
B．the Internet is the most popular tool for job hunters in the USA
C．Susan W. Miller’s company is helping people choose careers
D．California Career Services mainly serves university students
小題3:How many ways of finding a job are mentioned in the passage?
A．Three.B．Four.C．Five.D．Six.

查看答案和解析>>

科目：初中英語(yǔ) 來源：不詳 題型：閱讀理解

Hello! I am Julia. My mom and I are from the U.S.A. . I am thirteen now. I’m in Class 6, Grade 7. Lingling is my friend. She is from Yunnan. Her QQ number is 52656523. We are in the same school. She is in Grade 7, too. But she is in Class 7. She is fourteen. My mom is Nancy. She is a teacher in my school. She has a nice car.
根據(jù)短文內(nèi)容，選擇正確答案。
(       )1. How old is Julia?
A. 13             B. 14                C. 15
(       )2. Lingling’s QQ number is        ?
A. 52656523         B. 52655633           C. 52655623
(        )3. Lingling is in        ?
A. Class 6, Grade 7.      B.Class 7,Grade 7.   C.Class 7, Grade 6.
(        )4. Where is Nancy from?
A. China            B. England            C. the U.S.A.
(        )5. Which is RIGHT(哪一項(xiàng)是正確的)?
A. Lingling is from the U.S.A.        B. Nancy has two cars.  
C. Julia, Lingling and Nancy are in the same school.

查看答案和解析>>

科目：初中英語(yǔ) 來源：不詳 題型：閱讀理解

Fish and apple soup'？Yes, and you won't believe how delicious it is. This first came out of a restaurant in Singapore, but it is now very popular as the soup du jour in Chinese restaurants.  Ingredients (serves 4):
1. Whole fish
2 apples, quartered,
4-6 ginger slices (姜片)
1 bunch of spring onions, cut into pierces
1 red tomato, cut into 8 pierces ，oil. salt and pepper
Methods:
l. Remove the bones from the fish.
2 Pour oil into a pan. Fly the ginger slices, and the spring onions Add the fish hones and oil.
3. Add enough water and boil it for about 15 to 20 minutes,
4. Add the apples, the fish and the tomato. When the apples go soft, ads salt and pepper,
小題1:This passage is probably_________.
A．a(chǎn) poemB．a(chǎn) piece of newsC．a(chǎn) storyD．a(chǎn) recipe
小題2:The name of the soup in Chinese restaurants is_________.
A. du jour soup D. tomato soup C. union soup D. ginger soup
小題3:The underlined word "quartered" means_________.
A．榨汁B．切成四份C．洗凈D．炸碎
小題4:If you want to cook the soup for 8 people, you will need _____ red tomatoes.
A．1B．2C．3D．4
小題5:In what order should you add the ingredients while cooking the soup?
A．a(chǎn)pples, fish and tomato—ginger slices and spring onions—oil—fish bones
B．oil—fish bones—ginger slices and spring onions—apples, fish and tomato
C．oil—ginger slices and spring onions—fish bones—apples, fish and tomato
D．ginger slices and spring onions—fish bones-apples, fish and tomato—oil

查看答案和解析>>

科目：初中英語(yǔ) 來源：不詳 題型：閱讀理解

If we want to deal with the association(社交) between boys and girls properly, here are some “dos and don’ts” for you to follow.
Keep a normal and healthy state of mind. Our schools and classes are made up of boys and girls. It is very nature for the boys and girls to make friends with each other. We should make as many friends as possible. We should keep touch with the other sex(性別) in public instead of in secret.
Don’t be too nervous or too shy. If you are a shy person, you can also find a way out. First of all, you can make friends with the students who have the same interest and hobby as you. As both of you have much in common, you may have much to talk about. If you keep doing like that, little by little, you will gladly find you are also as free to express yourself as others.
Don’t fall into the ditch of early love. The boys and girls at a adolescence (青春期) are rich in feeling. They are easy to regard the friendship as a sign of love and fall in love with each other at an early age. In my opinion, early love is a green apple that can’t be eaten. An apple won’t taste sweet until it is full ripe. Boys and girls at middle school are too young to carry the heavy duty of love. Do keep out of early love.
小題1:We should keep touch with the other sex in following ways EXCEPT _______.
A．with a good state of mindB．in real friendship
C．in publicD．in secret
小題2:What does the underlined word “ditch” mean?
A．波浪B．泥潭C．圈套D．迷惑
小題3:The main idea of the passage is to _______.
A．tell students to keep away from early love
B．tell students how to make friends
C．teach boys how to talk with girls
D．give some advice on how to associate between boys and girls

查看答案和解析>>

科目：初中英語(yǔ) 來源：不詳 題型：閱讀理解

閱讀短文，根據(jù)內(nèi)容判斷正誤。正確的選“A”，錯(cuò)誤的選“B”
Blogs (博客) are the place where young people go to reveal(釋放) their souls（靈魂）. Many people enjoy the freedom in blogging. Some, however, find that putting one’s life online can have a price. Some students in America got suspensions (暫停) because on their blogs they posted threatening words to their teachers.
Recent surveys found that nearly one fifth of teens who have access to the Web have their own blogs. And 38% of teens say they read other people’s blogs. By comparison, about a tenth of adults have their own blogs and a quarter say they read other people’s online journals.
With the development of the Internet, more and more people will be engaged in blogging.
In another survey, 79% of teens agreed that people at their age aren’t careful enough when giving out information about themselves online. Besides, careless blogging can also affect blog viewers. When you are angry or frustrated, your blog is the first place you turn to. The words you post then may not be rational which you may regret(后悔) later. To reduce the negative effect, change the permission setting and make such posts “private” so that only you can read them.
As long as you are careful with what you post, blogging is a great means of staying in touch with friends and displaying one’s creative works.
小題1:      Blogs are the place where people go online to express themselves freely.
小題2:     The fact that some American students got suspensions is used to show that people should not put their life online. 

20070212

 
小題3:      The underline word “rational” in the fifth paragraph probably means reasonable（合理的）.

小題4:     The passage is mainly about advantages and disadvantages of blogs.
小題5:     Recent surveys found that over 50％ of teens who have access to the Web have their    own blogs.

查看答案和解析>>

科目：初中英語(yǔ) 來源：不詳 題型：閱讀理解

Water is very important to living things．Without water there can be no life on the earth．All animals and plants need water．Man also needs water．We need water to drink．to cool our food and to clean ourselves．Water is needed in offices，factories and schools．
Water is needed everywhere．There is water in seas；rivers and lakes ,Water is found almost everywhere．Even in the driest part of the world．there is some water in the air．You cannot see or feel it when it is a part of the air．The water in the seas，rivers and lakes is a liquid。The water in the air is a gas，and we call it water vapor．
Clouds are made of water．They may be made of very small drops of water．They may also be made of snow crystals(結(jié)晶體)．Snow crystals are very，very small crystals of ice．Ice is frozen water．It is a solid．There can be snow and ice everywhere in winter．
(   )4．Where Can we find water?
A．We can find water when it turns into vapor．
B．Water can be found almost everywhere
C．We can see water in deserts here and there．
D．Water is only in seas and rivers．
(   )5．We must protect water resources because       ．
A．crops need water        B．a(chǎn)ll living things need water
C．a(chǎn)ll animals need water    D．a(chǎn)ll plants need water

查看答案和解析>>

同步練習(xí)冊(cè)答案