It is easier to float in the ocean than it is to float in a swimming pool. Do yo

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It is easier to float in the ocean than it is to float in a swimming pool. Do you know why?
Ocean water is full of salt— and salt water can hold up more weigh than fresh water. See for yourself!
You Will Need:
● 3 cups of warm water
● Measuring cup (量杯)
● Wide-mouthed jar
● Salt
● Spoon
● Raw (生的)potato
You Will Do:
1. Pour 1.5 cups of warm water into the jar.
2. Add 1/3 cup of salt.
3. Stir(搅拌) until the salt is completely dissolved.
4. Add another 1.5 cups of water. Pour it slowly over the back of the spoon into the jar so that the two liquid will not mix together.
5. Gently place the potato into the jar. Do not drop it.
What Will Happen:
The potato will sink— but only halfway!
Why?
Salt water is heavier than fresh water, so it will stay on the bottom. The fresh water will remain on top.
The potato is heavier than the fresh water, but it is lighter than the salt water. That is why the potato will sink halfway down.
小题1:In the experiment, what should you do right after you pour the water over the spoon?

A．Add the salt to the water.	B．Stir the salt into the water.
C．Place the potato in the jar.	D．Pour warm water into thejar.

小题2:In Step 4 of the experiment, why do you pour the water over the spoon “slowly”?

A．It is easier to see what you are doing.

B．It pushes the fresh water to the bottom.

C．It will keep the water from coming out.

D．It will keep the liquids from mixing together.

小题3:In which step of the experiment do you add the salt?

A．Step 1

B．Step 2

C．Step 3

D．Step 4

小题4:What does the underlined word “gently” mean?

A．Carefully

B．Quickly

C．Secretly

D．Silently

答案

小题1:C
小题2:D
小题3:B
小题4:A

解析

试题分析：本文介绍了一个证明盐水的浮力比淡水的浮力大的实验。
小题1:C 细节题。根据You Will Do:中的5 Gently place the potato into the jar. Do not drop it说明C正确。
小题2:D 细节题。根据Add another 1.5 cups of water. Pour it slowly over the back of the spoon into the jar so that the two liquid will not mix together中的so that the two liquid will not mix together指这两种液体不要混在一起。故D正确。
小题3:B 细节题。根据You Will Do:中的2 Add 1/3 cup of salt.说明B正确。
小题4:A 推理题。根据Gently place the potato into the jar. Do not drop it中的Do not drop it不要扔下去，说明要轻轻地放，故A正确。
点评：本文考查的细节题特多，答题时在文章找到对应的地方，用笔进行标记，这有利于后期有时间检查时可以立刻找到答案的位置。仔细理解作者所讲的意思，再结合选项，通过排除法和自己对全文的把握，选出正确答案。

举一反三

Researchers at San Diego Zoo have been studying what has been described as the “secret language” of elephants. They have been monitoring（监测） communications between animals that cannot be heard by human ears.
The elephant’s call will be familiar to most people, but the animals also give out growls (低吼). Their growls, however, are only partly audible (听得见的); two-thirds of the call is at frequencies that are too low to be picked up by our hearing. To learn more about the inaudible part of the growl, the team attached (附在……上面) a microphone sensitive to these low frequencies and a GPS tracking system to eight of the zoo’s female elephants. The researchers could then relate the noises the animals were making to what they were doing. Matt Anderson, who led the project, told BBC News, “We’re excited to learn how they interact and contact with one another.”
The team has already learned that pregnant females use this low frequency communication to announce to the rest of their long gestation (妊娠期) of over two years, in the last 12 days we see the low part of the growl, which we can’t hear. This we believe is to announce to the rest of the herd that the baby is upcoming,” said Dr Anderson.
The researchers believe that this also warns the elephants to look out for coming danger. “You may think that a baby calf of about 300 pounds would not be as open to predation (捕食) as other species,” he says. “But packs of hyenas (袋狼) are a big threat in the wild.”
Female elephants are only in season for around four days every four years and these calls can be heard by males more than two miles away.
小题1:Why some elephants’ call is called “secret language”?

A．Because it can’t be heard by human ears.

B．Because it can only be heard by female elephants.

C．Because people don’t know its meanings.

D．Because people haven’t studied it completely.

小题2:By using a sensitive microphone and a GPS tracking system, the researchers wanted to find out .

A．where the elephants usually go

B．what the elephants’ growls really mean

C．how mother elephants raise baby calves

D．how elephants protect their babies.

小题3:A pregnant elephant uses inaudible growls to .

A．show the location where she is staying

B．ask for help when she losses her way

C．scare away the enemy

D．let others know she will have a baby

小题4:What is the passage mainly about?

A．The elephants can speak like people.

B．The wild elephants’ ways to fight against enemies.

C．The “secret language” between elephants.

D．The special life of female elephants.

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___1____ Maybe you thought that they were just happy. After all, you probably sing or whistle when you are happy.
However, they sing most of the time for a very different reason. ____2___ Some scientists believe that birds do sing some of the time just because they are happy.
Do you know what a “territory” is? A territory is an area that an animal, usually the male, claims(声称)as its own. ____3___ No other families of the same species are welcome. Your yard and house are your territory where only your family and friends are welcome. If a stranger should enter your territory and threaten you, you might shout. Probably this would be enough to frighten him away. If so, you have actually scared the stranger away without having to fight him. A bird does the same thing. But he expects an outsider almost any time, especially at nesting(筑巢)season. So he is screaming all the time, whether he can see an outsider or not.__4__.
Birds sing loudest in the spring when they are trying to attract a mate and warn others not to enter the territory of theirs. You can see that birds have a language all their own. ___5__

A．Only he and his family are welcome there.

B．Most of it has to do with attracting mates and setting up territories.

C．Have you ever wondered why birds sing?

D．Their singing is actually a warning to other birds to stay out of their territory.

E. Have you ever wondered why birds sing?
F. Most of the language is widely used.
G. This screaming is what we call a bird’s song, and it is usually enough to keep an outsider away.

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Travis laughed as he tore at the wrapping paper on his birthday present．He was so    16 ! Finally, he would have the coolest pair of name-brand basketball shoes．
All the guys on his team were wearing the name-brand shoes of a popular basketball   17  , Chuck Hart．    18   Hart was criticized for his poor sportsmanship（运动员风范） and infamous（臭名远扬的）   19 , he was a great player．In fact, Travis wasn"t thinking about Hart" s behavior; he had only expected to see Hart" s 20  on the side of the box．The first indication that something was   21  came as he tore away the last piece of paper．Not Hart" s．The new shoes were the name-brand of another player, Robert Ryann, who was   22   for his amazing work in the community．
Travis"s hands   23  ; his heart stopped．It wasn"t that the Ryann shoes weren"t nice, but what would his friends think ?
They were the wrong shoes and Travis would be   24  by the other players． When he looked up into his dad" s eyes, however, Travis knew he 25  tell him． ""Thanks, Dad．I was really hoping for shoes," Travis said as he pulled the shoes out of the box．
Next morning his dad drove him to school．When they   26  in front of his destination, Travis slowly opened the car door．Just then, his dad stopped him．
"Hey, Travis, wait a minute, look"…" his dad said 27   "Travis, I know those aren" t the shoes you had hoped for, but I saw the names of the two guys and made a（n）   28   The guy whose name is on those shoes," he said, pointing down at Travis’s feet, "is someone I   29   .Do you know how often Ryann has found himself in   30 ?"
"No," Travis said．
" Never．He" s never talked back to his coach or started a fight, and he" s a team player．You could have acted like a   31  when you didn"t get the shoes you wanted, Travis,   32  you were polite and made the best of it．You have    33 , like the guy whose name is on these shoes．I" m hoping that someday, your name will be on the coolest pair of shoes I" 11 ever see．"
When Travis looked down at his feet, he saw the shoes   34   . His dad had used his mind and heart to give the son a thoughtful   35   .

小题1:

A．surprised

B．ashamed

C．excited

D．worried

小题2:

A．team

B．player

C．coach

D．game

小题3:

A．Unless

B．If

C．Because

D．Although

小题4:

A．skill

B．performance

C．behavior

D．action

小题5:

A．name

B．photo

C．sign

D．model

小题6:

A．strange

B．wrong

C．true

D．funny

小题7:

A．known

B．encouraged

C．adopted

D．influenced

小题8:

A．fell

B．froze

C．shook

D．folded

小题9:

A．questioned

B．noticed

C．teased

D．attacked

小题10:

A．mustn"t

B．needn"t

C．wouldn"t

D．couldn"t

小题11:

A．pulled up

B．put up

C．took up

D．turned up

小题12:

A．peacefully

B．hesitantly

C．delightedly

D．naturally

小题13:

A．choice

B．effort

C．comment

D．mistake

小题14:

A．believe

B．miss

C．admire

D．remember

小题15:

A．danger

B．anger

C．sorrow

D．trouble

小题16:

A．teammate

B．adult

C．kid

D．student

小题17:

A．so

B．and

C．but

D．or

小题18:

A．honor

B．courage

C．dream

D．belief

小题19:

A．clearly

B．carefully

C．patiently

D．differently

小题20:

A．gift

B．look

C．hope

D．lesson

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Unlike many surfers who sought the perfect wave, my interests always lay beneath the sea" s surface in a world I could only imagine and dream of．When I was twelve, I made my first adventures in the deep．Later I would learn how to dive, expanding my world of exploration many times over．
Perhaps the greatest turning point in my life came when I was in high school and I wrote a letter to the famous Scripps Oceanographic Institution, asking how I might learn more about the sea．A kind scientist answered my letter and told me how to apply to Scripps for a summer scholarship, which I received．During one of their courses that summer, I met Dr．Robert Norris, a marine geologist．He loved the sea almost as much as I did．Soon he suggested I consider his school, the University of California, for my study．One year later I became a member of the freshman class．
Now my love affair with the sea became a serious endeavor（艰苦的努力）．If I wanted to be an undersea explorer, I needed to learn as much as I could about the laws of the physical world that controlled the environment I wanted to enter．The undersea world is not our natural world．It is unforgiving to those who make mistakes．At its greatest depths the water temperature is near freezing, the pressure is eight tons per square inch, and it is totally dark．It is easy to get lost in such a world．I needed to learn a lot about geography, navigation, geology, biology, and many other things．
I decided another important thing for me to do was to join the U．S．Navy．If I was going to be an undersea explorer, I would have to lead men and women on dangerous adventures where they might get hurt, and I didn"t want that to happen．
In the Navy I learned discipline, organization, and how to motivate and lead people on adventures so that we could explore the wonders of the deep．
Finally, the time came to put all that I had learned to use, to go forth with a team of men and women and explore an adventure I am still on and hope to be on for many years to come．
小题1:What happened to the author at the age of twelve?

A．He dreamed about undersea exploration．

B．He began to swim under the deep water．

C．He surfed on big waves for the first time．

D．He learned to dive off the cliffs．

小题2:In college, the author took many different types of courses because he

A．was told it was easy to get lost in exploration

B．was advised to take them by Dr．Robert Norris

C．thought they were needed to fully understand the ocean

D．believed it would help him succeed in the Navy

小题3:The author joined the Navy to ______．

A．develop his leadership skills

B．get along with people under stress

C．learn about the dangers of the ocean

D．gather specific information about ocean life

小题4:Which word can best describe the author?

A．Imaginative．

B．Optimistic．

C．Independent．

D．Ambitious．

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Some wonderfully creative uses of X-rays have been in the world of art．But the most impressive one is to uncover what has been covered up．Details unfolded by an X-ray of a painting can " t be seen any other way．For example, in the past, paintings were often repaired if small pieces of paint fell off the canvas （帆布）． These repairs cannot be seen just by looking at the painting．It takes an X-ray to discover where the repairs have been made．
An X-ray of a painting is one of the best ways to tell if it was created by a famous painter or if it is a forgery（赝品）．If there is a question as to whether an old master has painted a certain painting or not, X-rays are made and compared to those of paintings that are known to be original．If the brushstrokes （笔迹） , for example, are shown to be totally different than in other work done by a certain artist, then the painting is proved to be a fake copy．
Since modern paints are usually made from different materials than paints of hundreds of years ago, the image they leave on an X-ray film looks different．This is another way X-rays can be used to spot a forgery．A modem artist will try to make a forgery look hundreds of years old by painting dirty varnish on it or by using artificial means to get the varnish to look cracked．To the naked eye the forgery may look old, but when a careful study of the X-ray image is made, the deception is obvious．
It was common many years ago for an artist to finish a painting, decide it wasn"t any good, and paint a completely different picture on top of it．Or artists would paint over others" work —it was their version of recycling．Taking an X-ray is the only way to find out if there is a picture underneath the picture you see with your eyes．Sometimes museums will be more interested in the painting beneath than the one on top, and will restore the older one by having the top layer painstakingly removed．
小题1:What is the main purpose of the article?

A．To provide information to police who are looking for stolen art．

B．To persuade art dealers to check for fake copies before selling art．

C．To explain how modern technology can be applied in unique ways．

D．To help artists restore damaged artwork to its original appearance．

小题2:According to the passage，X-rays are used to ______．

A．make repairs on paintings in the past

B．identify the authenticity of an artwork

C．change the materials of a forgery

D．remove the recyclable paints

小题3:In Paragraph 3, the word "deception" probably means ______．

A．comparison

B．drawback

C．trickery

D．judgement

小题4:Which is the best title for the passage?

A．X-ray Detectives

B．Creative Uses of Technology

C．Forgery Studies

D．X-ray Painting Techniques

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