call it the summer learning setback. Put simply, it means the longer kids are out of school, the more they
forget. The only thing they might gain is weight. Recent studies show that children gain weight more
quickly in the summer vacation than when they are in school.
Most American schools follow a traditional nine-month calendar. Students get winter and spring
breaks and about ten weeks of summer vacation. Some schools follow a year?round calendar. They
hold classes for about eight weeks at a time, with a few weeks off in between. But many experts point
out that the number of class days in a year-round school is generally the same as in a traditional school.
Last year, a study at Ohio State University reported that year-round students did not learn any more
than other students. Lead researcher Paul von Hippel said "year-round schools don"t really solve the
problem of the summer learning setback. They simply spread it out across the year".
Across the country, research shows that students from poor families fall farther behind over the
summer vacation than other students. Experts say this can be prevented. They note that many schools
and local governments offer the programs that can help.
But calling them "summer schools" could be a problem. The director of the summer learning center
at Johns Hopkins, Ron Fairchild, recently wrote about this issue on his blog.
He said that in American culture, the idea of summer vacation is connected to the beliefs about
freedom and the joys of childhood. He said research with groups of different parents in Chicago and
Baltimore found that almost all strongly disliked the term summer school. They said it created an image
of children being forced to do work they missed during the school year.
B. More kids drop out of school.
C. Kids become poor in learning.
D. Kids take part in all kinds of activities.
B. every few weeks
C. every three months
D. every four months
B. the year-round calendar is better than the traditional one
C. the traditional calendar is as bad as the year-round one
D. the year-round calendar is the same as the traditional one
B. whose families are poor
C. who are too naughty
D. who don"t work hard
B. must choose to take part in one of the programs
C. should do what they like and enjoy themselves
D. must be forced to make up for their poor lessons
What exactly are white lions?"They are a color variation of regular lions,"says William
Swanson,director of animal research at the Cincinnati Zoo,in Ohio.
White lions are the result of a rare color gene mutation(变异).When both a male and
a female lion carry the same white genes,there is a good chance that one or more of their
cubs(幼兽)will be born with white fur.
Not many lions carry the white mutation.In nature,it"s rare.A mutation can make an
animal"s survival more difficult.For example,being white makes it harder for the animal to
mix with its surroundings.Mutations also can cause physical problems,so those animals
generally do not survive long enough to reproduce.
But sometimes white lion cubs are born among wild lions,especially in two areas of
South Africa.
In 1975 two white cubs were spotted in the wild in South African reserve.They were
seized and sent to a zoo.Today about 500 cubs of those two white lions and a few others
known to have the white color gene live around the world in zoos,circuses,farms and private
preserves.
White lions may be extremely rare in the wild,but breeders(饲养动物的人)know how
to create more of them.This has created serious concern and debate.
White lions continue to exist only because they are inbred by people-fathers and
daughters,sisters and brothers.Scientists worry that it also will cause health issues for white
lions.
Inbreeding to create white lions as moneymaking attractions is only one concern.Another
concern is that some people want to release captive-bred(人工繁殖的)white lions into
the wild in South Africa to restore balance to the ecosystem.However,not everyone agrees
that releasing these white lions into the wild is a good idea.Dan York of Hillsdale College
has been studying white lion genetics and is worried.He says that because so many of today"s
white lions are inbred,it could spread health problems.If they breed with wild lions,they"ll
pass on the genetic problems to the wild population.
Instead of releasing captive-bred white lions,York suggests that South Africa concentrate
on protecting all of its wild lions.That would ensure the safety of the wild population of lions,
which may produce healthy white cubs in the future.
a.itsfurcontrastssharplywiththesurroundings
b.themutationmaycausephysicalproblems
c.itislikelytobeattackedbywildlions
d.itishuntedbyhumanbeings
A.a,b
B.a,d
C.a,c
D.b,d
B.bred in human-controlled environments with restricted settings
C.produced by breeding among closely related members
D.born among wild lions and kept in the zoo
B.their fur can be of great use
C.people want to keep white lions as pets
D.people want to study the genes of white lions
B.White lion cubs born among wild lions are more healthy than captive-bred ones.
C.White lions shouldn"t be kept in zoos or circuses.
D.The ecosystem in South Africa is being seriously damaged.
B.color gene mutation is common among lions
C.South Africa is taking strict measures to protect its wild lions
D.white lions will disappear from the earth soon
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.
T hese 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 e-mail suggesting a
simple way to understand 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.
B.Africa and Europe
C.North America and Europe
D.Australia and Europe
B.plant buds
C.the leaves of a plant
D.the roots of a plant
B.be protected
C.be watered as much as possible
D.be given much auxin
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.
B.When and how to prune plants?
C.Scientists help cut the mystery behind pruning
D.The great scientist-Prezemyslaw Prusinkiewicz
Hills,California,plan to pick up trash during their city"s annual cleanup.At the same time,Wissam Raed,12,
will be busy volunteering too.Thousands of miles away in Lebanon,Wissam plans to put on a play at an
orphanage and bring potted plants to elderly people at a senior citizen center.
Some other children like Nathan White,10,have personal reasons for volunteering.Nathan"s grandmother
died of a heart attack.To help raise money for medical research,Nathan participated in Jump Rope for
Heart.He and five other boys took turns jumping rope for two and half hours and collected more than US
$1,200 in donations for the American Heart Association.
Millions of children around the globe lend a hand to their communities every year.Schools and parents
also contribute to the rise in youth service.For example,many schools offer community service activities for
students to join.Teachers either combine volunteer work with classroom lessons or make service work a
requirement.Parents,on the other hand,encourage their kids to volunteer and do it with them.
Community service is particularly important in this depression time.As the need for monetary support
and other aid has increased,many charitable organizations have experienced a significant drop in donations.
Camille and other children who volunteer thousands of hours annually can fill in some of the gaps.
According to research, kids who start volunteering are twice as likely to continue doing good deeds
when they are adults.So,grab a paintbrush,a trash bag,or whatever you need to help your community.You"ll
love how you feel after helping others.Even dirty work can be lots of fun,if it"s for a good cause.
B.To ask charity organizations to serve the community.
C.To urge children to take part in volunteering activities.
D.To propose alternatives for doing community services.
B.Families and schools help to make community service popular.
C.Children now depend more on their teachers than on their parents.
D.Nathan White had a special reason to raise money for medical research.
B.It teaches children to take care of the sick.
C.It gives charity organizations some needed help.
D.It encourages parents and teachers to work together.
B.Children will probably leave school and work as volunteers.
C.Organizing sports events for the school is a kind of community service.
D.Children who do volunteer work are more likely to grow up to be caring adults.
professor David DeSteno, and his colleagues, who are conducting a research to determine how humans
decide to trust strangers.
The interdisciplinary(跨学科的) research project,funded by the National Science Foundation (NSF) ,
is being conducted together with Cynthia Breazeal,director of the MIT Media Lab"s Personal Robots
Group, Robert Frank,an economist,and David Pizarro,a psychologist,both from Cornell.
The researchers are examining whether gestures could affect our trustworthiness judgments."People
tend to mimic(模仿)each other"s body language,"said DeSteno,"which might help them develop intuitions
(直觉) about what other people are feeling."
This project tests their theories by having humans interact with the social robot,Nexi,in an attempt to
judge her trustworthiness.Without knowing the participants,Nexi has been programmed to make gestures
while speaking with selected participants-gestures that the team thinks could determine whether or not
she"s considered trustworthy.
During the first part of the experiment, Nexi makes small talk with them for 10 minutes, asking and
answering questions about topics such as traveling,where they"re from and what they like most about living
in Boston.
"The goal was to create a normal conversation with accompanying movements to see what the mind
would intuitively(直觉地) collect about the trustworthiness of another,"said DeSteno.
The participants then play an economic game called "Give Some",which asks them to determine how
much money Nexi might give them at the expense of her individual profit.Meanwhile,they decide how
much,if any,they"ll give to Nexi.The rules of the game allow for two distinct outcomes:higher individual
profit for one and loss for the other,or relatively smaller and equal profits for both partners.
"Trust mightn"t be determined by only one gesture,but rather a "dance" that happens between the
strangers,which leads them to trust or not trust the other," said DeSteno,who will continue testing their
theories by seeing if Nexi can be taught to predict the trustworthiness of human partners.
B.Three fields.
C.Four fields.
D.Five fields.
B.the voice communication
C.the gesturebased communication
D.the online communication
B.intuitively watch the trustworthiness
C.accompany the robot closely
D.play an economic game
B.a kind of entertainment
C.a simple gesture
D.one person"s gestures
reasons are various."School Refusal",formerly known as"School Phobia",is an actual
anxietybased disorder.Many children are vague about their complaints and unable to be sure
what is making them anxious,so it is sometimes regarded as typical childhood will fullness.
However,the effects of constant school refusal can be farreaching for your child"s education.
So,where"s the line between what"s normal and what"s not?"You need to look at whether
it is affecting the child or family"s normal life,"explains Christopher Kearney,Ph.D.In other
words,if a child"s grades are suffering from frequent absences or a parent"s job is disturbed,
it is time to look closely at the issue.Parents should listen carefully to children who say they
can"t go to school because of "untestable things"such as stomachaches or headaches.While
these complaints alone don"t necessarily indicate school refusal,there may be deeper problems
if combined with general complaints about school,talks of threats at school and so on.
There are different kinds of behavior in school refusal.Some children are influenced by their
friends who skip school to hang out with their friends,showing a sense of rebellion(叛逆).
Some children cling to their mothers,screaming at the thought of having to enter the school
building.
However,that doesn"t mean that getting a child back into the classroom is impossible.
According to Maryann Roth,a school psychologist and guidance counselor(顾问),parents
should attempt to make the child get back to school,no matter how hard it is.Working closely
with school officials and possibly a specialist to create a plan is a necessary step.
B.unclear
C.curious
D.unusual
B.are afraid of endless tests
C.want to stay with their parents
D.feel bored and unsafe at school
A.take the problem seriously if their daily life is disturbed
B.discuss the seriousness of the problem with their children
C.take their children to see the doctor immediately
D.keep their children away from their rebellious friends
B.explain the phenomenon of “School Refusal” and how to treat it
C.remind parents to take good care of their children
D.explain that “School Refusal” is normal and not serious
- 1下面是1950——1991年,美、日、西欧在世界工业生产中所占的比重(%)。图中反映的信息不包括[ ]A.美国进
- 2热带雨林的脆弱性表现在A.生物残体分解快B.植物生长速度快C.养分几乎都储存在地上植体内D.群落以高大的乔木为主
- 3下图是国家标准委对酒后驾驶、醉酒驾驶的界定标准(以100ml血液中的酒精含量为依据)。对此认识正确的是①质变是最变的必然
- 4已知:如图,有一根木棒AB重合在数轴上,若将木棒在数轴上水平移动,则当A点移动到B点时,B点所对应的数为20;当B点移动
- 5已知则( )A. B.C.D.
- 6若x+y+57=y-z+17=x-z+44=0,则x2+y2+z2=______.
- 7分解因式:2x2-18=( )。
- 8一个正三棱锥的底面边长为6,侧棱长为15,那么这个正三棱锥的体积是______.
- 9玻璃在加热过程中,下列说法正确的是[ ]A.玻璃吸热后温度不变B.玻璃吸热后温度持续上升C.玻璃吸热后温度先上升
- 10【题文】已知集合,,,且,则整数对的个数为( )A.20B.
- 1因式分a3+ab2+2a2b=______.
- 2关于万有引力的说法正确的是 [ ]A.万有引力只有在天体与天体之间才能明显地表现出来B.一个苹果由于其质量很
- 3下列图形中,是中心对称图形的是( )A.B.C.D.
- 4如图 所示,下列工具的使用中,属于费力杠杆的是[ ]A.镊子B.独轮车C.起子D.扳手
- 5下列离子方程式中正确的是______________(1)氢氧化亚铁溶于稀硝酸中:Fe(OH)2 + 2H+ = Fe2
- 6建立和谐社会,人与自然和谐相处,人与社会和谐相处,始终是人类孜孜以求的一个社会理想,也是我们现代中国的奋斗目标。下列哲学
- 7With a lot of difficult problems____________ , the manager f
- 8右图是某同学连接的实验实物图,使用四节电动势为1.5V的干电池做电源,合上开关S 后,发现A、B灯都不亮,他采用下列两种
- 92008年以来,联合国安理会多次通过打击索马里海盗的决议,授权各国使用海陆空力量打击索马里海盗。从中可以看出联合国的重要
- 10十七大突出强调高举中国特色社会主义伟大旗帜,就是要表明,我们党将始终不渝地坚持以***理论和“三个代表”重要思想为指导,