Every year when the Italian artist Michelangelo"s (1475-1564, 意大利文艺复兴时期著名雕刻家、画家、
建筑师) birthday comes around, computer users all over the world are filled with fear (害怕) and use their
computers with care. Some may even choose not to turn on their computers on March 3. All this fear and care
are just because a deadly computer virus is ready to cause damages (破坏) on that day.
What"s a computer virus then? Why do people get so afraid of it?
A computer virus is, in fact, a little program that is put into other programs and that does something bad.
It is called a virus because, like any real-life viruses such as AIDs virus, it reproduces itself. And when these
programs are run, the virus is brought to life. It hides itself in your computer system waiting for the right
moment to make damages. And at the same time it keeps producing itself by copying itself onto other programs.
The Michelangelo virus waits until the artist"s birthday comes around, and then it will wake up to do very
bad things like destroying you files (毁坏文档). So next time when you turn on your computer, look out for
computer viruses!
B. was born on March 3, 1475
C. died six centuries ago
D. died on March 3, 1564
B. a kind of computer virus will come on that day
C. a deadly computer virus called "the Michelangelo virus" will wake up and then damages that day
D. something will easily go wrong with computers
B. a kind of real-life virus
C. a kind of virus like AIDS virus
D. also a kind of program which is placed into other programs and which makes damages
B. only on March 3
C. on Fridays
D. only on some famous artists" birthdays
kind of loneliness is not serious. In fact, it is quite normal. For some people, though, loneliness can last for
years. Now researchers say there are three different types of loneliness.
The first kind of loneliness is temporary (暂时的). This is the most common type. It usually disappears
quickly and does not require any special attention. The second kind, situational loneliness, is a natural result
or a particular situation-for example, a family problem, the death of a loved one, or moving to a new place.
Although this kind of loneliness can cause physical problems, such as headaches and sleeplessness, it usually
does not last for more than a year.
The third kind of loneliness is the most severe. Unlike the second type, chronic (长期的) loneliness usually
last more than two yeas and has no specific cause. People who experience habitual loneliness have problems
socializing and becoming close to others. Unfortunately, many chronically lone people think there is little or
nothing they can do to improve their condition.
Psychologists (心理学家) agree that one important fact in loneliness is a person"s social contacts, e.g,
friends, family members, co-workers, etc. We depend on various people for different reasons. For instance,
our families give us emotional support, our parents and teachers give us guidance, and our friends share similar
interests and activities. However, psychologists have found that, though lone people may have many social
contacts, they sometimes feel they should have more. They question their own popularity.
Psychologists are trying to find ways to help habitually lonely people for two reasons: they are unhappy
and unable to socialize and there is a connection between chronic loneliness and serious illness such as heart
disease. While temporary and situational loneliness can be a normal, healthy part of life, chronic loneliness
can be a very sad, and sometimes dangerous condition.
B. Just ignore it
C. Go to see a doctor
D. Ask your teachers for guidance
B. lonely people don"t have many social problems
C. one problem of loneliness is a person"s social contacts
D. we depend on various people for different reasons
B. Chronic loneliness can cause serious illness
C. Chronic loneliness cannot be overcome
D. A, B, and C are all correct
B. Loneliness and Diseases
C. Loneliness and Social Contacts
D. Chronic Loneliness
or her second year of high school is required to take a class in driver"s education. However, unlike other
courses, it is not given during the regular school year. Instead it is a summer course.
The course is divided up into two parts: class time for learning laws and regulations, and driving time to
practise driving. Class time is not unlike any other class. The students study the basic traffic laws from a text
to pass the written driving test that is given to anyone who wants to get a driver"s license.
Driving time is a chance for the students to get behind the wheel (steering wheel) and practise starting
steering, backing up, parking, switching lanes, turning corners, and all the other maneuvers (操作) required
to drive a car. Each student is required to drive a total of six hours. The students are divided up into groups
of four. The students and the instructor go out driving for two hour blocks of time. Thus, each student gets
half an hour driving time per outing. The instructor and "driver" sit in the front seats and the other three
students sit in the back.
After the student has passed the driver"s education course and reached the appropriate age to drive (this
age differs in every state but in most cases the person must be 16 years old), they can go to a designated (指
定的) state office to take their driver"s test, which is made up of an eye examination, a written test, and a
road test. The person must pass all three tests in order to be given a driver"s license. If the person did well in
his or her driver"s education class, he or she will pass the test with flying colors and get a driver"s license.
B. is given to anyone wanting to get a driver"s license
C. is carried on at the same time as other courses
D. is offered to all the students of Grade 2 in high schools
B. get half an hour driving
C. drive for two hour blocks of time
D. go out driving for twelve times
B. They must be 16 years of age.
C. They should go to have their driver"s test.
D. They ought to do well in their driver"s course.
B. quickly
C. colorfully
D. successfully
that protect the environment such as solar energy are becoming possible alternatives.
Increasing demand for clean, renewable energy is driving a growing market for solar energy products..
Two of the main types of products that take advantage of solar energy are passive and active solar products.
These two types of systems differ in how they are constructed and can also differ greatly in cost. Passive solar
technology can be used to heat air or water directly using the sun"s energy. Unlike an active solar application,
passive solar set-ups accomplish their task without the use of additional electrical components, such as fans
that need an external electricity supply. Some solar space heating or water heating systems are active solar
heating systems that have various components that call for external power sources. Because of their simplicity
compared with active systems, passive solar heating systems generally are cheaper than active ones.
In addition to these solar heating systems, there are also solar power system available. Rather than using the
sun"s energy for heating applications, these systems change solar energy into electricity. An important part of
these products is called photovoltaic cells, which generate electricity from light. As sunlight falls on a
photovoltaic cell, the light"s energy is changed into electricity that can then be used to power many kinds of
electronic devices. Because of the complicated technology involved, these kinds of solar power systems can
be very expensive.
When considering what kind of solar heating or power system to install (安装) in your home or business,
be sure to purchase your equipment from a reputable manufacturer who will be able to help you with any
necessary repair.
Solar energy application
Batteries can power anything from small sensors to large systems. While scientists are finding ways to
make them smaller but even more powerful, problems can arise when these batteries are much larger and
heavier than the devices themselves. University of Missouri(MU) researchers are developing a nuclear energy
source that is smaller, lighter and more efficient.
"To provide enough power, we need certain methods with high energy density (密度)", said Jae Kwon,
assistant professor of electrical and computer engineering at MU. "The radioisotope (放射性同位素) battery
can provide power density that is much higher than chemical batteries."
Kwon and his research team have been working on building a small nuclear battery, presently the size and
thickness of a penny, intended to power various micro / nanoelectromechanreal systems (M/NEMS). Although
nuclear batteries can cause concerns, Kwon said they are safe.
"People hear the word "nuclear" and think of something very dangerous," he said, "However, nuclear power
sources have already been safely powering a variety of devices, such as pace-makers, space satellites and
underwater systems."
His new idea is not only in the battery"s size, but also in its semiconductor (半导体). Kwon"s battery uses
a liquid semiconductor rather than a solid semiconductor.
"The key part of using a radioactive battery is that when you harvest the energy, part of the radiation energy
can damage the lattice structure (晶体结构) of the solid semiconductor," Kwon said, "By using a liquid semicon
ductor, we believe we can minimize that problem."
Together with J. David Robertson, chemistry professor and associate director of the MU Research Reactor,
Kwon is working to build and test the battery. In the future, they hope to increase the battery"s power, shrink
its size and try with various other materials. Kwon said that battery could be thinner than the thickness of
human hair.
B. He developed a chemical battery.
C. He is working on a nuclear energy source.
D. He made a breakthrough in computer engineering.
B. to introduce nuclear batteries can be safely used.
C. to describe a nuclear-powered system.
D. to introduce various energy sources.
B. test the power of nuclear batteries
C. decrease the size of nuclear batteries
D. reduce the damage to lattice structure
B. test the power of nuclear batteries
C. decrease the size of nuclear batteries
D. reduce the damage to lattice structure
B. book review
C. newspaper ad
D. science fiction story
like a fat chicken, eats green leaves, has the stomach of a cow and has claws (爪) on its wings when young.
They build their homes about 4.6m above the river, an important feature (特征) for the safety of the young.
It is called the hoatzin.
In appearance, the birds of both sexes look very much alike with brown on the back and cream and red
on the underside. The head is small, with a large set of feathers on the top, bright red eyes, and blue skin. Its
nearest relatives are the common birds, cuckoos. Its most striking feature, though, is only found in the young.
Baby hoatzins have a claw on the leading edge of each wing and another at the end of each wing tip. Using
these four claws, together with the beak (喙), they can climb about in the bushes, looking very much like
primitive birds must have done. When the young hoatzins have learned to fly, they lose their claws.
During the drier months between December and March hoatzins fly about the forest in groups of 20 to 30
birds, but in April, when the rainy season begins, they collect together in smaller living units of two to seven
birds for producing purposes.
B. The relatives and enemies of hoatzins.
C. Primitive birds and hoatzins of the Amazon.
D. The appearance and living habits of hoatzins.
B. they have claws on the wings
C. they eat a lot like a cow
D. they live on river banks
B. They could fly long distances.
C. They had four wings like hoatzins.
D. They had a head with long feathers on the top.
B. To protect themselves better.
C. To keep themselves warm.
D. To produce their young.
- 1坚持四项基本原则,也就是[ ]A.坚持公有制,坚持人民民主专政,坚持中国共产党的领导和马克思列宁主义、***思想
- 2_____ in a simple living atmosphere was what her parents wis
- 3金刚石和石墨物理性质差异较大的原因是A.形状不同B.密度不同C.碳元素排列不同D.碳原子排列不同
- 4材料一:《“十二五”节能减排综合性工作方案》提出:到2015年,全国万元国内生产总值能耗要下降到0.869吨标准,比去年
- 5宋初为了加强专制主义中央集权,对军权、行政权、财权和司法权都实行了集中。下列对其有关叙述有误的是A.设立枢密院,直接统领
- 6下列方程:,,x+y=0,x-y=0中,所能满足的方程有[ ]A.1个 B.2个 C.3个 D.4个
- 7物体作匀加速直线运动,已知第1s末的速度是6m/s,第2s末的速度是8m/s,则下面结论正确的是[ ]A.物体的
- 8人粪尿是人体排出的废物完全没有用途了。 ( )
- 9下列关于顶端优势的叙述中错误的是[ ]A.顶芽生长衰弱,促进侧芽生长B.除去顶芽,侧芽生长被抑制C.顶芽优先生长
- 10读图回答:(1)地点A的位置:纬度______.经度______.(2)地点C的位置:纬度______.经度______
- 1In the reading room, we found her _____ at a desk, with her
- 2下图为同学们熟悉的植物,请据图回答(1)夏天,池水变绿的原因是图中___________类植物大量繁殖造成的。此类植物有
- 3一平面内,两条直线的位置关系是______.
- 4 —___________?—It ‘s black.A.What’s this B.Who is it
- 5Could you please __________ me __________ my English?[ ]
- 6下列反应属于取代反应的是( )①CH3COOCH3+CH3CH2OH―→CH3COOCH2CH3+CH3OH②2CH3
- 7世界上每个成熟的民族都有属于自己的特有文化形态和文化个性,而这种特有的文化就成为民族亲和力和凝聚力的重要源泉。 国家的发
- 8如何避免和治理泥石流呢?(1)小明回忆了以前对摩擦力的探究:用弹簧测力计沿水平方向拉着一个木块,在不同的平面上做匀速直线
- 9I like black __________ red, _________ I don’t like yellow.
- 10某化学兴趣小组探究炼铁的原理,装置如图所示。请回答有关问题: (1)实验进行一段时间后,玻璃管A中出现的现象为_____