精英家教网 > 高中英语 > 题目详情
阅读理解
     Today we tell you about some new understanding of why cutting the main branch of a plant or tree
can lead to better development.
     The findings are from researchers on two_continents.Professor Prezemyslaw Prusinkiewicz of the
University of Calgary in Canada led the research with scientists from Britain and Sweden.Their study
appears in the Proceedings of the National Academy of Sciences.
     Researchers have known since the 1930s that the actively growing tip of a plant produces a hormone(荷尔蒙) called auxin(生长素). This hormone flows down the main stem.Scientists say the auxin has
an indirect effect on buds(芽) on the side of the stem to prevent branching.
     These buds themselves also produce auxin.The research suggests that to grow, they have to be able
to export the hormone into the main stem.But the flow from the stem tip prevents them from doing this.
The researchers wanted to find out how this blocking happens.
     Professor Prusinkiewicz is on leave in Australia, but he sent us an email suggesting a simple way to
underst and the process.Think of a major road crowded with traffic.So many cars are on the main road
that the cars on the side roads cannot enter.
      The stem is like the crowded main road.The new research shows that the buds on the side cannot
export their auxin into the main stem because it is too full.But if that main shoot is pruned(修剪), other
buds below it can start exporting.They are no longer prevented from growing.
     Ottoline Leyser from the University of York says that after a plant is pruned, all the inhibited(被抑制的) shoot tips compete with each other to grow.In doing this, the branches influence each other's growth.
Nearby shoot tips are more likely to affect each other than those that are far apart from each other.
      Professor Leyser says the strongest branches grow best, wherever they may be on the plant.The
study found that the main shoot grows the best of all not because of its position at the top of the plant,
but mostly because it got there first.

1. The underlined part "two continents" in Paragraph 2 refers to "________".
A. Asia and Africa  
B. Africa and Europe
C. North America and Europe
D. Australia and Europe

2. Professor Prusinkiewicz compares the cars on the side roads to ________.
A. plant stems  
B. plant buds
C. the leaves of a plant  
D. the roots of a plant

3. To make the buds on the side of the stem to grow better, the main shoot should ________.
A. be cut off
B. be protected
C. be watered as much as possible
D. be given much auxin

4. According to the passage, which of the following is TRUE?
A. Researchers have recently found out that the growing tip of a plant produces hormones.
B. Auxin has a direct effect on buds to keep branches from growing.
C. Buds on the side of the stem can't produce hormones.
D. In order to grow, the buds on the side of the stem export the hormones into the main stem.
练习册系列答案
相关习题

科目:高中英语 来源:山东省枣庄市2010届高三第一次模拟考试英语试题 题型:050

阅读理解

  April 22,2010 will be the 18th celebration of the annual Take Our Daugluers to Work Day(TOD), a project the National Ms.Foundation for Women of America(NFW)developed to expose girls to expanding opportunities for women in the workplace.

  The program offers, millions of girls a first - hand view of the many career opportunities available in their futures.Now that women make up 46 peroent of the U.S.workforce, girls can find role models in every occupational field-from politics to molecular biology to professional athletics, to name just a few.TOD encourages girls to focus on their abilities and opportunities, not just their appearance.

  The NFW developed the project more than a decade ago to address the self-esteem problems that many girls experience when they enter adolescence.At school, boys often receive more encouragement in the classroom, especially in math.science and computer science, the academic fields that tend to lead to the highest salaries.Women receive on average only 73 cents for every dollar that men are paid.and remain vastly underrepresented(数量不足)in top executive positions and technology fields.TOD aims to give girls the confidence and inspiration they need to develop successful careers, particularly in non-traditional fields.

  Perhaps because the program had become so widespread and successful, TOD had been criticized for excluding boys.and it was expanded in 2003to include boys.The program's official website states that the program was changed in order to provide both boys and girls with opportunities to explore careers at an age when they are more flexible in tenns of gender stereotyped roles."We should also show boys that becoming a child care provider is as acceptable a choice as becoming a police officer or CEO," added Sara K.Gould.executive director of the NFW.

(1)

The purpose for having a Take Our Daughters to Work Day is ________

[  ]

A.

to encourage girls to get top paying jobs

B.

to let girls spend more time with their mothers

C.

to show girls possibilities for work and careers

D.

to give girls a chance to visit their mothers' offices

(2)

Why are women underrepresented in some fields such as technology?

[  ]

A.

They are not interested in these fields.

B.

They are not encouraged to work in these fields.

C.

They are not paid the same as men in these fields.

D.

They are not allowed to be educated in these fields.

(3)

TOD was criticized because some people ________.

[  ]

A.

thought it was not fair to boys

B.

did not like having children at work

C.

did not have daughters to take to work

D.

would rather have their daughters stay at home

(4)

Which of the following is true according to the passage?

[  ]

A.

Boys are now included on Take Our Daughters to Work Day.

B.

Women and men have always been treated equally at work.

C.

Homemaking and raising children are jobs for girls only.

D.

Girls grow up receiving more attention than boys.

(5)

What can we learn from Sara K.Gould's words?

[  ]

A.

Boys are sometimes more careful and responsible than girls.

B.

It is most suitable for women to look after children at home.

C.

Aboy's life ambition should be to become an officer or CEO.

D.

It is also acceptable for boys to do what girls are supposed to.

查看答案和解析>>

科目:高中英语 来源:广东省期中题 题型:阅读理解

阅读理解。
     John was waiting for the girl whose heart he knew, but whose face he didn't. Thirteen months
ago, in a Florida library he took a book off the shelf and took great interest in the notes in the
margin(页边空白). The soft handwriting reflected a thoughtful soul and insightful mind.
In front of the book, he discovered the previous owner's name, Miss Hollis Maynell. With time
and effort he located her address. He wrote her a letter introducing himself and inviting her to
correspond.
    During the following years the two grew to know each other through the mail. John requested
a photograph, but she refused. She felt that if he really cared, it wouldn't matter what she looked
like. Later they scheduled their first meeting-7:00 pm at Grand Central Station in New York.
   "You'll recognize me, " she wrote, "by the red rose I'll be wearing on my lapel." So at 7:00 he
was in the station looking for the girl with the red rose.
    A girl in a green suit was coming toward him, her figure long and slim and her eyes were blue.
Almost uncontrollably he made one step closer to her, and just at this moment he saw Hollis
Maynell-a woman well past 40. The girl was walking quickly away. He felt as though he split(裂开)
in two, so keen was his desire to follow the girl, and yet so deep was his longing for the woman
whose spirit had truly accompanied him and upheld his own.
   He did not hesitate. He squared his shoulders and said to the woman, "I'm John, and you must
be Miss Maynell. I am so glad you could meet me; may I take you to dinner?"
   The woman smiled, "I don't know what this is about, son," she answered, "but the young lady
in the green suit begged me to wear this rose on my coat. And she said if you were to ask me out
to dinner, I should tell you that she is waiting for you in the restaurant across the street. She said
it was some kind of test!"
1. We can infer from the passage that_______.
A. John succeeded in winning the heart of Miss Maynell  
B. Miss Maynell was a very funny woman  
C. John had know the secret and prepared in advance 
D. John got Miss Maynell's address from the book.
2. We can learn from the passage that_____.
A. it is useful to read often in the library.             
B. Miss Maynell was brighter than John
C. you must make sure that he is honest before you make a friend
D. only the true love can stand the test     
3. Which of the following is right about the book?
A. The woman put the book there on purpose.
B. Miss Maynell's name greatly aroused John's interest. 
C. Part of the book was written by Miss Maynell.
D. Possibly the book was once Miss Maynell's but now it was owned by the library. 
4. The woman who wore the rose on her coat _____.
A. didn't know the girl who gave her the rose
B. was an acquaintance (熟人) of Miss Maynell
C. showed great admiration for the clever girl
D. was moved deeply by the true love between the two youngsters.
5. According to the passage, Miss Maynell begged that woman to wear the rose to _____.
A. compare with her and gain an advantage over her
B. make sure that the man was there on time
C. check if he was the man she wrote to
D. see whether he was a real man who wasn't just fond of appearance

查看答案和解析>>

科目:高中英语 来源:江苏高考真题 题型:阅读理解

阅读理解。
                             I
     The opening ceremony of this famous
yearly competition (比赛) will begin at
11:30 a.m. There will be music groups,
rappers and children's chorus. 12:25p.m.
sees the introduction of the eaters who
come from all over the world. At 12:40
p.m., the historic 12-minute all-you-can-
eat competition will begin.The world
record stands at over 50 hot dogs and
buns in 12 minutes. Will anyone beat the
record this year?
     Viewing is available on a first-come-
first-served basis. Television crews are
invited to use a two-tiered (两层) stage
three metres from the main stage. The
area in front of the main stage is kept
for photographers and television cameras
without tripods (三脚架).
                                   II
     Few periods in history are as exciting as
the time when the Vikings (北欧海盗) were
known-and sometimes feared-throughout
Scandinavia, the British Isles, Russia, all the
Mediterranean, Africa and even America.
     Frojel is a family-based society, which
aims to relive and describe the Vikings from
a harbor-Frojel, on the Swedish island of
Gotland, Frojel was one of the richest trading
centers in the Viking world.
     The members of the society aim to recreate
the clothing, weapons, tools, jewellery, games,
food and furniture of that long-gone period.
They want to enjoy an escape to a simpler, more
relaxed time, with like-minded people. They will
also use the items they have made to relive that
age at various public entertainments.

1. According to Advertisement I, the famous yearly competition is _____.
A. a music competition
B. an eating competition
C. a cooking competition
D. a picture-taking competition
2. People who come to watch the competition earliest may _____.
A. get the best watching position
B. get the best food
C. watch whatever they want to
D. take good pictures
3. The best title for Advertisement II would be _____.
A. The Vikings
B. Reliving of the Vikings
C. Frojel
D. A Viking Reliving Society
4. From the advertisement we know that Frojel used to be _____.
A. a Viking club
B. a family-based society
C. a European island
D. a trading center

查看答案和解析>>

科目:高中英语 来源:江苏高考真题 题型:阅读理解

阅读理解。
1. Which of the following is discouraged by the Friends organization?
A. To build massive complexes for public amusement.
B. To prevent possible damages to the National Park.
C. To help protect and improve the Park for all to enjoy.
D. To sponsor publicationsand projects in local school.
2. One of thebenefits for members of Friends is to _____.
A. have Friends' goods free of charge
B. visit any place not open to the public
C. take part in work parties if they want to
D. give talks in their fields on current issues
3. The purpose of this poster is to invite more people to _____.
A. raise money for the Friends organization
B. join the Friends organization and be members of it
C. work as managers for Pembroke shire National Park
D. enjoy the landscape of Pembroke shire National Park

查看答案和解析>>

科目:高中英语 来源:安徽省模拟题 题型:阅读理解

阅读理解。
Name: Julia Rosetti
Email: n1950215@droid.fit.qut.edu.au
Location: Brisbane, Australia
Age: 18
Sex: Female
Drugs: No
Alcohol: No
Sports/ Activities: I used to do a lot of ballet and stage work, my ambition was to be a professional
dancer before I got sick. Nowadays I love to read, and other stuff like that, as well as spending a lot of
time with my family and friends.
Grades: I finished high school last year, and I haven't started college because I've been sick. But I got
subject prizes in three subjects and high as in the rest.
Favorite Subject: I loved Music, English, History and Biology. Hard to pick a favorite - they're all so
different.
Volunteer Work: It all depends on what you call "volunteer". Nothing really official, but I spend a lot of
my time working and playing with really sick kids, and they come to me for advice a lot.
What My Future Goals Are: I'd either like to go on to do stage work, or work with kids with serious
illnesses. I haven't decided which, yet.
What I do in My Spare Time: Talk to my friends and my family. Hang around with my hospital friends. Watch TV. Go to the movies when I can. I love going on picnics and other outdoorsy stuff.
How I'd Change the World: No question. Cure cancer. Eradicate it forever.
Largest Problem: Sometimes, I think it's having too many choices, and having too many expectations
and others having too many expectations of you. And all the implications (牵连) of this.
Why Would I Make a Good Counselor (顾问): I really want to help other people. I've made that my
life's ambition, to help as many people as I can.
Qualifications: I spend a lot of time doing this sort of stuff "unofficially" - I am the Discussion Manager
on a discussion list for seriously ill young people. People also write to me because of my homepage, often wanting advice, which I try to give them.
1. What can we infer about Julia Rosetti?
A. She is ill now with a cancer.
B. She has had an operation.
C. She is curing people of cancer.
D. She is working in a hospital.
2. The underlined word "eradicate" most probably means _____.
A. get out of
B. put an end of
C. break up
D. set aside
3. The underlined word "you" stands for _____.
A. Julia Rosetti herself
B. all her friends in her life
C. the person she refers to
D. everyone including herself
4. Which of the following statements is true about Julia Rosetti?
A. She had wanted to become a doctor.
B. She had done very well at college.
C. She often visits hospitals in her spare time.
D. She has her own homepage on the Internet.

查看答案和解析>>

同步练习册答案