Did you ever wonder why leaves change colors in autumn, or how it happens? Here’s a quick explanation.
First of all, you’ve probably noticed that not all trees lose their leaves. There are two major types of trees: deciduous trees and evergreens. Evergreens keep their leaves and stay green all year long. The deciduous trees are the ones that lose their leaves each year.
In autumn, the days begin to get shorter. The sun is also lower in the sky at noon, which causes temperatures to be cooler. The combination of less sunshine and lower temperatures is what causes the deciduous trees to drop their leaves. In winter, deciduous trees “go to sleep”, sort of like a bear goes into hibernation.
Leaves are the food factories for a plant. Unlike animals,plants make their own food by taking energy directly from the sun. Plants do this by using a chemical in their leaves called chlorophyll.
Chlorophyll is green. During the spring and summer the leaves of a deciduous tree look green because there is a lot of chlorophyll there. In autumn, however, the sunshine becomes more  scarce and the leaves on the trees stop making new chlorophyll. As the old chlorophyll starts to break down, the green color of the leaf begins to go away.
You’ve probably also noticed that the leaves of different kinds of trees change different colors. The leaves of some trees turn yellow or orange, while the leaves of other trees turn bright red or purple. The different colors are caused by the different chemical reactions that are happening in the leaves.
For example, the leaves of some trees turn yellow when the chlorophyll breaks down. When the green chlorophyll goes away, a yellow pigment in the leaf becomes visible. The yellow pigment, called cartenoid, was already there during the summer, but is was not easily seen because there was too much green chlorophyll.
In other trees where the leaves turn red or purple a different chemical reaction takes place. In those leaves the chlorophyll also breaks down, but another chemical reaction takes place at the same time. Chemicals in the leaves, called starches, begin to change into chemicals called anthocyanins, which give the leaves their red and purple colors.
So next time you see the beautiful colors of autumn you will also know the science behind that beauty.
46.   What is the correct term for trees that lose their leaves in the autumn?
A. Evergreens       B. Deciduous        C. Cartenoids  D. Anthocyanins
47.   Which of the following is NOT mentioned as a cause of trees dropping their leaves?
A. A change in temperature   B. The amount of daylight available
C. Extra chlorophyll         D. Chemical changes in the leaves
48.   If there are 50 evergreens and 10 deciduous trees in a forest, in autumn what color are most of the leaves in the forest likely to be?
A. Green B. Red and purple
C. Yellow        D. not enough information to determine the answer
49.   Which of the following is only present in leaves during the autumn?
A. Chlorophyll       B. Starch C. Cartenoids        D. Anthocyanins
50.   Where would such an article mostly likely be published?
A. In a book                   B. In a primary school science text book
C. In a magazine for young people       D. All are equally likely

Sometimes life makes more sense when you look at it in reverse (相反). That's certainly been true for me.
Last Christmas, at 39, I caught a disease which attacked my knees and eyes. At its worst I could hardly walk or see. For months I' d have to crawl (爬) across the floor to use the bathroom or get a drink of water when my husband wasn't home. For a while I could only see shapes and colors so I couldn't drive.
My parents kept begging me to let them come out to stay with me in Los Angeles, but our apartment is small and I knew there was nothing they could really do to help me. For the excellent health insurance my husband had through his job, I was receiving the best medical care possible.
My only problem was that I couldn't drive to my doctors' appointments and I didn't want my husband to keep missing work to drive me. Three days after I explained this to my parents, a check came from them with a note saying this was "taxi money". Several months later another check showed up from my brother to help make up our income since I wasn't able to work. It probably goes without saying that I was extremely grateful to have family members who could and would support me during the hard time.
In terms of my day-to-day existence, I live in a village within Los Angeles called Brentwood so I was able to walk to the local post office, market, bank, and library. But once there, I had to depend on the kindness of strangers to help me. Los Angeles is a big city, but I lived in a village with a wonderful community (社区) of people who were kind and patient.
Slowly I became well. Life was good again and I thought I had a clear understanding of the blessings (恩惠) this illness has provided.
【小题1】When the author's husband was at home, he __________.

A.was still busy working
B.often had a good rest
C.often helped her a lot
D.taught her to drive a car
【小题2】Why did the author not want her husband to drive her to her doctors' appointments?
A.Her husband didn't drive well.
B.Her husband was too busy.
C.She didn't want to affect his work.
D.Her doctor was far away from her.
【小题3】What is the fourth paragraph mainly about?
A.The help that the author received from her family members.
B.The influence of the author's disease on her family.
C.The author's thanks to her family members.
D.The way the author saw her doctors.
【小题4】What did the author feel about Brentwood?
A.She thought it was small but convenient.
B.She felt it was hard to live there.
C.She thought it was small and strange.
D.She felt warm and comfortable there.

Four years ago my sweet mom went to be with her Lord. She did it her way.
I got the call at work, and I headed home quickly. Mom and Dad lived on a small farm that they had owned since I was seven. I hated going there every weekend. There was nothing for a young girl to do but watch the one station on the old TV set, if the weather allowed reception.
My mom, on the other hand, loved the peace and quiet of the land and loved to work in the garden among her flowers and vegetables. The place was rustic, with no indoor plumbing or heat. We had a big wood stove in the kitchen that did its best to heat the little farmhouse, but it always seemed cold and too quiet to me.
In the evenings, my mom and I would sit for hours singing in the little kitchen. I sang the melody and Mom harmonized. Her favorite song was "Moon River" and we sang it over and over. Mom told me stories about how when I was a little girl, I could sing before I could talk. She loved to tell how my playpen(婴儿圈栏)sat in the kitchen next to the radio and there was one song I particularly loved called "Ivory Tower".
As time passed, I had my own children and went to visit every week or two. The kids loved the farm and the tractor rides with my dad. Me, well, I still hated the silence of the farm. While my mom loved to sit at her kitchen table and look out at her garden and flowers and retell all the old stories, I missed the hustle and bustle(喧闹)of my life at home. But I sat there listening quietly as she reminisced.
Now, I sat back in the silence and the silence was deafening so I finally leaned over to turn on an old radio. Music always comforted me.
My heart skipped a beat. "Moon River" was playing on the radio. I sat there stunned, with a tear running down my cheek, as I listened to every familiar note.
Then the radio announcer of this oldie station came on. "Here's one we haven't heard in a while," and an unfamiliar song began. I began to cry harder as I heard the words sung over the airwaves. "Come down, come down from your Ivory Tower...."
【小题1】 The writer didn’t like staying in the farm for the following reasons EXCEPT that ________.

A.it was too cold and quiet
B.she could only sing one song in the small farm
C.there was nothing more that could make her excited
D.The place was rustic, with no indoor plumbing or heat
【小题2】 From the first paragraph, we know that the writer’s mother ________.
A.passed away four years ago
B.left the small farm with Lord
C.left for Lord to live her own way
D.preferred to be with Lord
【小题3】The underlined word reminisced in the fifth paragraph probably means ________.
A.recalledB.comfortedC.shoutedD.sighed
【小题4】 Which of the following statements is NOT true according to the passage _______.
A.The writer was able to sing before she could speak.
B.The writer preferred to live a busy life in the city.
C.The writer was still quite familiar with the song "Ivory Tower".
D.The writer treasured all her childhood memories in the small farmhouse.
【小题5】 Which of the following would be the best title for this passage? _______
A.Cherish lifeB.My happy childhood
C.Our small farmhouseD.Mom’s music

Every year mobile phones develop. Imagining what they will look like and be able to do in 2020 is really a challenge. To help, experts have outlined three major mobile trends that they believe will have become reality by then.
Our phones will be so smart in 10 years’ time that they’ll know everything about our situation and warn us when something needs our attention. This is the top prediction of both Nokia and Google. They predict that our cars and home appliances will be able to communicate with our mobile. For example, fridges will tell your mobile to tell you to pick up milk on the way back from work. While driving, your mobile will suggest that you take a different route because there’s a road accident up ahead.
The second trend is in gesture-based controls. People who know the iPhone’s touch-sensitive screen are already familiar with the technology. It translates hand movements into actions on-screen. But gestural communications will make the phone more convenient to use and may completely replace touchpads. According to industry insiders, the most immediate step forward in gestural technology will be in voice recognition. It’s believed voice recognition technology will speed up communications. It is quicker to speak than type. Eventually, phone screens will disappear.
The third major development will change our understanding of a mobile phone. From a single phone, the mobile will be developed into multi-part devices. It is opposite to the current trend in which mobile phones are combining the functions of cameras, music players and game consoles. The prediction is based on the idea that the world will become more wireless and all these—cameras, music players and game consoles—will be wirelessly connected. Mobile phones won’t need to contain these devices because users will be able to control them wirelessly through their phones.
【小题1】The first paragraph serves as          .

A.a lead-inB.a conclusionC.a summary D.a supporting fact
【小题2】Which of the following is most likely to be the appearance of a mobile phone in 2020? 

【小题3】From the text, we can learn that the future mobile phones will          .
A.drive cars for us
B.be controlled by the users’ voices
C.be controlled by home appliances
D.be very big together with separated multiple parts
【小题4】The text mainly tells us          .
A.three major trends of mobile phones
B.what mobile phones will look like in 2020
C.the future mobile phones are gesture-based
D.some new functions of the present mobile phones

Squirrels often communicate with whistles, chirps and chucks, which sound like the word “chuck”. Whistles and chirps are like the sounds that many birds make.Now scientists have translated some of their squirrel-speak.
Hare, a professor of zoology at the University of Maniloha in Winnipeg, and his team managed to record squirrels' alarm calls.The researchers studied the sounds and then played them back to 60 wild squirrels, which the scientists approached individually with a video recorder to capture(抓拍)their reponses.Some squirrels lifted their heads up and became.Alert(警惕的).Creatures that were more frightened simply ran for their lives and dived into caves.
"In effect then, whistles that mix with chucks say 'there's an enemy of average threat that's here', and whistles without chucks say 'there's an enemy of seemingly average threat around here somewhere', while pure chirps say, 'I'm hiding here because there's an immediate danger.' " Hare told.Discovery News.
Hare and some other researchers believe such sounds arc part of an advanced language that develops just as all other communication systems.
Although squirrels risk their lives when they call out to warn others of threats, other squirrels might admire this behaviour, thus increasingly the caller’s social status, like humans who look up to heroes. Hare added that other animals, such as birds, probably understand at least some squirrel language, since they also may benefit from the alarm calls.
In fact, another Canadian study found that deep-voiced, black-capped chickadees have their own language too.According to certain research, there are a lot of tidings in chickadees' calls, such as directing fellows' activities, keeping in contact between mates, and raising alarms.
While chickadees and other birds are often welcomed into gardens by homeowners, squirrels are frequently viewed as pests(害兽). Hare wishes a greater understanding of the complex social lives and communication systems of squirrels will provide “hope that humans will gain a greater appreciation and stop doing harm to these animals”.
【小题1】The text mainly talks about

A.the study on the language of squirrels
B.the comparison between squirrels and chickadees
C.the calling for the protection of squirrels
D.the ways for squirrels to escape from their enemies
【小题2】If a squirrel is in a very dangerous situation, it would probably make ____.
A.whistles with chucksB.pure chirps
C.whistles without chucksD.repeated chucks
【小题3】The underlined word “tidings” in pardgmph 6 probably means ____.
A.difficultiesB.poisesC.messagesD.languages
【小题4】What can be learned from this text?
A.Squirrels communicate with cach other as humans do.
B.Some squirrels understand the recorded alarm calls.
C.Other animals also well understand the language of squirrels.
D.Birds such as chickadees don’t have their own language.

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