can make sounds to warn their young of danger. They have their own way to make the young birds do certain
things.
The jackdaw is a kind of blackbirds that lives in Europe. Jackdaws live together in flocks (群). Young
jackdaws do not know their enemies. When an older jackdaw sees a dog, it makes a loud rattling (格格响的)
sound. The younger birds know this sound means an enemy is nearby. The sound warns them to know their
enemies.
If a young jackdaw is in a dangerous place, a jackdaw parent flies over him from behind. The parent bird
flies low over the young bird"s back. The parent"s tail feathers (羽毛) move quickly from side to side. It is
trying to say, "Follow me."
At the same time, the parent calls out, "Key-aw, key-aw." The parent means, "Fly home with me." The
young bird then follows the older home.
Young jackdaws do not have to learn what certain sounds mean. They know the meaning of these sounds
from the time they hatch.
B. Australia
C. America
D. Africa
B. makes a loud sound
C. flies away
D. fights the dog
B. Dogs are the most dangerous enemies for jackdaws.
C. Young jackdaws know the meaning of their parents" sound when they grow older.
D. Some birds can give certain information to one another.
managed to land a satellite on the planet Earth, and it has been sending back signals as well as photographs ever
since.
The satellite was directed into an area known as Manhattan (named after the great Venusian astronomer
Prof. Manhattan, who first discovered it with his telescope 20000 light years ago).
Because of excellent weather conditions and extremely strong signals, Venusian scientists were able to get
valuable information as to feasibility (可行性) of a manned flying saucer (碟) landing on Earth. A press
conference was held at the Venus Institute of Technology.
"We have come to the conclusion, based on last week"s satellite landing," Prof. Zog said, "that there is no
life on Earth."
"How do you know this?" the science reporter of the Venus Evening Star asked.
"For one thing, Earth"s surface in the area of Manhattan is made up of solid concrete and nothing can grow
there. For another, the atmosphere is filled with carbon monoxide (一氧化碳) and other deadly gases and
nobody could possibly breathe this air and survive."
"What does this mean as far as our flying saucer program is concerned?"
"We shall have to take our own oxygen with us, which means a much heavier flying saucer than originally
planned."
"Are there any other dangers that you discovered in your studies?"
"Take a look at this photo. You see this dark black cloud hovering (盘旋) over the surface of Earth? We
don"t know what it is made of, but it could give us a lot of trouble and we shall have further tests before we
send a Venus Being there."
"Over here you will notice what seems to be a river, but the satellite findings indicates it is polluted and the
water is unfit to drink. This means we shall have to carry our own water, which will add even greater weight
to the saucer."
"If all you say is true, won"t this set back the flying saucer program several years?"
"Yes, but we shall continue as soon as the Grubstart gives us the added funds." Prof. Zog replied.
to _____.
B. the possibility of making a first-rate flying saucer
C. the feasibility of sending a Venus Being to Earth
D. the possibility of directing a flying saucer into Manhattan
their flying saucer program because _____.
B. the Earth"s atmosphere is filled with deadly gases
C. there is a low level of oxygen for Venusians
D. there is no air on the planet of Earth
B. the mass of tiny drops of water floating above Earth
C. the mass of small things moving through the air
D. the dark clouds gathering before a storm breaks
on like this
B. that there is a point in spending billions to land a flying saucer on Earth
C. that pollution has become so serous a problem on Earth that even Venusians find life there unbearable.
D. that it is difficult if not altogether impossible, to land a manned flying saucer on Earth
For some time past it has been widely accepted that babies-and other creatures-learn to do things because
certain acts lead to "rewards"; and there is no reason to doubt that this is true. But it used also to be widely
believed that effective rewards, at least in the early stages, had to be directly related to such basic physiological
(生理的) "drive" as thirst or hunger. In other words, a baby would learn if he got food or drink or some sort
of physical comfort, not otherwise.
It is now clear that this is not so. Babies will learn to behave in ways that produce results in the world with
no reward except the successful outcome.
Paousek began his studies by using milk in the normal way to "reward" the babies and so teach them to
carry out some simple movements, such as turning the head to one side or the other. Then he noticed that a
baby who had enough to drink would refuse the milk but would still go on making the learned response with
clear signs of pleasure. So he began to study the children"s response in situation where no milk was provided.
He quickly found that children as young as four months would learn to turn their heads to right or left if the
movement"switched on a display of lights-and indeed that they were able to learn quite complicated turns to
bring about this result, for instance, two left or two right, or even to make as many as three turns to one side.
Papousek"s light display was placed directly in front of the babies and he made the interesting observation
that sometimes they would turn back to watch the lights closely although they would "smile and bubble" when
the display came on. Papousek concluded that it was not primarily the sight of lights which pleased them, it
was the success that they were achieving in solving the problem, in mastering the skill, and that there exists a
fundamental human urge to make sense of the world and bring it under intentional control.
B. will meet their physical needs
C. will bring them a feeling of success
D. will satisfy their curiosity
B. would carry out learned movements when it had enough to drink
C. would continue the simple movements without being given milk
D. would turn its head to right or life when it had enough to drink
B. be rewarded with milk
C. please their parents
D. be praised
B. the satisfaction of certain physiological needs
C. their strong desire to solve complex problem
D. a fundamental human urge to display their learned skills
temperature. This helps us decide what to wear. 1_____. We want our food to be a certain coldness
in the refrigerator. We want it a certain hotness in the oven. If we don"t feel well, we use a thermometer
to see if we have a fever. We keep our rooms a certain warmth in the winter and a certain coolness in
the summer.
Not all the thermometers use the same system to measure temperature. We use a system called the
Fahrenheit scale. But most other countries use the Centigrade scale. Both systems use the freezing and
boiling points of water as their guide. 2_____.
The most common kind of thermometer is made with mercury (水银) inside a clear glass tube. As
mercury (or any other liquid ) becomes hot, it expands. As it gets colder, it contracts (收缩). That is
why on hot days the mercury line is high in the glass tube. 3_____.
First. Take a clear glass juice bottle that has a cap; fill the bottle with coloured water. Tap a hole in
the center of the cap using a hammer and thick nail. Put the cap on the jar. Then stick a plastic straw
(吸管) through the nail hole. 4_____.
Finally. Place a white card on the outside of the bottle and behind the straw. Now you can see the
water lever easily. 5_____.
As the temperature goes down, the water will contract, and the lever in the straw will come down.
Perhaps you will want to keep a record of the water lever in the straw each morning for a week.
lives.
B. Thermometers measure temperature, by using materials that change in the same way when they are
heated or cooled.
C. Now that you know this rule you can make a thermometer of your own that will work.
D. The water will rise in the straw. As the temperature of the air goes up, the water will expand and rise
even higher.
E. They label these in different ways. On the Fahrenheit scale water freezes at 32 degrees and boils at 212
degrees. On the Celsius scale water freezes at 0 degrees and boils at 100degrees.
F. Take wax (you may use an old candle if you have one) and melt some of it right where the straw is
struck into the cap to seal (把..粘住) them together.
G. People use thermometers which are made by themselves when travelling around the world.
This article gives some suggestions on how to give an effective speech.
So, you have to give a speech-and you"re terrified. You get nervous, you forget what you want to say,
you stumble over words, you talk too long, and you bore your audience. Later you think, "Thank goodness,
it"s over. I"m just no good at public speaking. I hope I never have to do that again."
Cheer up! It doesn"t have to be that bad. Here are some simple steps to take the pain out of speech
making. Ask yourself the purpose of your speech. What is the occasion? Why are you speaking? Then,
gather as many facts as you can on your subject. Spend plenty of time doing your research. Then spend
plenty of time organizing your material so that your speech is clear and easy to follow. Use as many examples
as possible, and use pictures, charts, and graphs if they will help you make your points more clearly. Never
forget your audience. Don"t talk over their heads, and don"t talk down to them. Treat your audience with
respect. They will appreciate your thoughtfulness.
Just remember: be prepared. Know your subject, your audience, and the occasion. Be brief. Say what you
have to say and then stop. And be yourself. Let your personality come through so that you make person-to-
person contact with your audience.
If you follow these simple steps, you"ll see that you don"t have to be afraid of public speaking. In fact,
you may find the experience so enjoyable that you volunteer to make more speeches! You"re not convinced
yet? Give it a try and see what happens.
B. a poor speaker can never change
C. always make a short speech
D. it is hard to make a speech
B. many people are happy to give a speech
C. many people do not prepare for a speech
D. many people talk too long
B. look at the ceiling
C. look down upon them
D. use words and ideas that are too difficult
B. a lecturer does not need to organize his speech
C. research is important in preparing a speech
D. there are simple steps you can take to improve your speaking ability
B. How to Give a Good Speech
C. How to Prepare for a Speech
D. Try to Enjoy a Speech
country as well. Whether or not solar energy can save your money depends on many things. Where you
live is one factor and the type of home you have is another. Things like insulation (绝缘材料), present
energy costs, and the type of system you buy are added factors.
Using solar energy can help save our precious fuel. As you know, our supplies of oil and gas are very
limited. There is just not enough on hand to meet all our future energy needs. Sooner or later Mother Nature
will say that"s all. The only way we can delay hearing those words is by starting to save energy now and
by using other sources, like the sun.
We won"t have to worry about the sun"s running out of energy for another several billion years or so.
Besides, the sun doesn"t offer as many problems as other energy sources. For example, fossil fuel (矿物
燃料) adds to already high pollution levels. With solar energy, we will still need sources of energy, but we
won"t need as much. That means we can cut down on our pollution problems. With all these good points,
why don"t we use more solar power? There are many reasons for this. The biggest reason is money. Until
now, it was just not practical for a home owner to put in a solar unit. There were cheaper sources of energy.
All that is changing now. Solar costs are starting to equal the costs of oil and electricity. Experts say
that gas, oil and electricity prices will continue to rise. The demand for electricity is increasing rapidly. But
new power plants will use more gas, oil or coal. Already in some places the supply of electricity is being
rationed (限量供应). Solar energy is now in its infancy (初期). It could soon grow to become a major part
of our nation"s energy supply.
B. Solar energy.
C. Energy and pollution.
D. Energy and money.
B. become home owners
C. get rid of present energy
D. save our precious fuel
B. several hundred years
C. several billion years
D. several thousand years
B. Energy from natural gas would not pollute our living environment.
C. Energy from the sun would not pollute our living environment.
D. Energy from oil would not pollute our living environment.
B. so we will build more power plants
C. and the supply of electricity will be rationed throughout the country
D. so we don"t need it
- 1碱性电池具有容量大、放电电流大的特点,因而得到广泛应用。锌-锰碱性电池以氢氧化钾溶液为电解液,电池总反应式为:Zn(s)
- 2关于能源的利用,下列说法正确的是( )A.大量使用石油产品会造成大气污染,所以应该停止开采石油B.和平利用核能特别要注
- 3亲爱的同学们,你能从郭沫若先生的诗中找出半坡氏族的特点吗?“彩陶形制美,画纹亦多珠。或则呈人面,或则呈双鱼。农耕既普及,
- 4某元素原子的最外层电子数是次外层电子数的3倍,且最外层电子数与次外层电子数之和小于10。该元素为( )。A.锂B.铍
- 5电视剧《闯关东》在多家电视台热播,剧中格格那文和鲜儿从王府出逃,路上正遇到军队抓住行人强行剪辫子。这一现象的普遍出现与下
- 6下列各句中,没有错别字的一项是A.雷曼***、美林被收购以及AIG面临的危机,使得全球金融市场再度风声鹤唳,一时间,世界金
- 7 He was so nervous during the test. No ________he didn’t pas
- 8Nancy Green lives _______, but she never feels _______. [
- 9下列物质能用相应单质直接化合而制取的是( )A.FeSB.FeCl2C.SO3D.NO2
- 10-Could you please tell me where __________? -Sure.
- 1G2图是我国某城市人口增长和人口自然增长率变化示意图。读图回答问题。小题1:从1998年开始,该市人口自然增长率呈负增长
- 2下列各式一定成立的是 [ ]A.a3=(﹣a)3B.﹣a2=|﹣a2|C.a3=|a3|D.a2=(﹣a)2
- 3承认矛盾的_________是坚持唯物辩证法的前提。 ____ 是正确认识和处理一切矛盾的关键。A.普遍性坚持具体问题
- 4城市流是人、物、信息、资金、技术等在城市间发生的流动现象。下表是2008年中国部分省级区之间的城市流强度(不包括港澳台)
- 5.Most of them have no doubt _______ he will pass the driving
- 6下列化学反应中,离子方程式表示正确的是 ( )A.澄清石灰水检验CO2气体:CO2 + Ca2++2OH-=Ca
- 7亚里士多德说:“我们确认自然生成的城邦先于个人,就因为(个人只是城邦的组成部分)每个隔离的人都不足以自给其生活,必须共同
- 8平面上动点P到定点F(1,0)的距离比P到y轴的距离大1,则动点P的轨迹方程为( )A.y2=2xB.y2=4xC.y
- 92008年5月12日,四川汶川发生里氏8.0级地震,国内外社会各界纷纷向灾区捐款捐物,抗震救灾。截止6月4日12时,全国
- 1022. _____ computer has been proved to be _____ important aid