Space is where our future is — trips to the Moon, Mars and beyond. Most people would think that aside from comets (彗星) and stars, there is little else out there. But, since our space journey started we have left so much trash there that scientists are now concerned that if we don't clean it up, we may all be in mortal(致命的)danger.

The first piece of space junk was created in 1964, when the American satellite Vanguard I stopped operating and lost its connection with the ground center. However, since it kept orbiting around the Earth without any consequences, scientists became increasingly comfortable abandoning things that no longer served any useful purpose in space.

It is estimated that there are now over 500,000 pieces of man-made trash orbiting the Earth at speeds of up to 17,500 miles per hour. The junk varies from tiny pieces of paint chipped off rockets to cameras, huge fuel tanks, and even odd items like the million-dollar tool kit that astronaut Heidemarie Stefanyshyn Piper lost during a spacewalk.

The major problem with the space trash is that it may hit working satellites and damage traveling spacecraft. Moreover, pieces of junk may collide with each other and break into pieces which fall back to the Earth. To avoid this, scientists have invented several ways for clearing the sky. Ground stations have been built to monitor larger pieces of space trash to prevent them from crashing into working satellites or space shuttles. Future plans include a cooperative effort among many nations to stop littering in space and to clean up the trash already there.

1.What was the first piece of man-made space trash ?

A. A camera. B. A tool kit.

C. A fuel tank. D. A broken satellite.

2.Why were scientists NOT concerned about space trash in the beginning ?

A. It no longer served any useful purpose.

B. It was millions of miles away from the Earth.

C. It did not cause any problems.

D. It was regarded as similar to comets and stars.

3.Which of the following statements is true about space junk ?

A. It is huge, heavy machines.

B. It never changes position.

C. It floats slowly around the Earth.

D. It may cause problems for space shuttles.

4.What has been done about the space trash problem ?

A. Scientists have cleaned up most of the trash.

B. Large pieces of space trash are being closely watched.

C. Many nations have worked together to stop polluting space.

D. Ground stations are built to help store the trash properly in space.

練習(xí)冊系列答案
相關(guān)習(xí)題

科目:高中英語 來源:河南省商丘市2017年高三下學(xué)期第三次模擬考試英語試卷 題型:閱讀理解

Some creative people see colors when they hear different sounds. Others hear voices when they see words and numbers. What they experience is called synaesthesia(通感)。

A study at the University of Sussex in the UK is finding out how to use synacsthesia to improve your IQ and memory. The study leaders Danil Bor has been working on exploring memory for a number of year. Bor says that carrying out these tests has given them the opportunity to find out more about how we use different kinds of memory.

Bor based his latest research on something scientists already know a lot about “chunks”. He explains that this is a way of parceling out large pieces of information into smaller units (chunks), with certain features or meanings, to make it easier to remember.” When I gave you my phone number, 01274737271, you probably remember it as 012-74-73-72-71, or something similar. If you can remember 012 and then 74, you can remember the rest by its features. You can get some amazing benefits from chunks.”

In this way, synacesthesia adds extra meaningful information to things that are different to remember, such as letters, numbers, or colors. This helps us remember things betters.” All these signs are pointing towards synaesthesia being connected to greater abilities to do certain things, certain jobs.” says Bor. “So, the study began as a way to test that.”

They wanted to see if they could create a way to learn about synaesthesia, and use its benefits to help everyone. In the study, they trained volunteers for 10 minutes a day for a week. The results were not huge, but impressive.

They discovered that after training, the volunteers were able to pass the normal synaesthesia tests and their IQ jumped up about 12 points. Although Bor believes they still need to test the increase in IQ with different groups of people, the result is very impressive. “It’s very useful to increases people’s IQs. Even when the group are already quite clever, like the students who take part in this study.” he said.

1.Which is the best title for this passage?

A. Synaesthesia, a Common Phenomenon B. Synaesthesia and Chunks

C. What Synaesthesia Tells Us? D. Synaesthesia Helps you Improve IQ

2.How does synaesthesia improve memory?

A. Synaesthesia adds news meanings to memory materials.

B. Synaesthesia is connected to greater abilities to do certain things.

C. Synaesthesia simplifies the memory process.

D. Synaesthesia blends blends various methods together.

3.What does “parcel out” in paragraph 3 mean?

A. Submit. B. Enlarge.

C. Break. D. Arouse.

4.From the passage, Bor feels ________ about the result of the test.

A. doubtful B. worried

C. optimistic D. uncertain

查看答案和解析>>

科目:高中英語 來源:K12教育質(zhì)量保障聯(lián)盟山東省2017屆高三5月打靶卷英語試卷 題型:七選五

How to revise for a test

Studying for tests may be one of the most difficult parts of school. 1. If you feel discouraged about an approaching test and need some directions for preparing yourself, consider using the following suggestions to help you out.

Aim foremost to understand the concepts.

Keep the important points in mind, and ignore unnecessary information. 2.

Ask for help.

When the need arises, it is best to receive help from the others. 3. You could also ask him/ her for a set of questions and answers that could help you memorize the information. You could also ask a family member or a friend for help.

Practice in everyday life.

Fit reviewing into everyday life by sticking up notes with sentences you need to remember for the test written upon them. 4. You could possibly put one on the bathroom mirror, one at the table and another by the TV. This is optional but highly recommended.

5.

Find out how much you remember certain things and what’s missing. Decide what you did well in and what you did not so well in. This may boost your chances of getting more marks in the assessment and may also help you remember for next time. For instance, if you are struggling on maths problems based on geometry, then put this down as something that you need to review more than the subjects you are good at.

Review often but little.

Do not push yourself and try reviewing everything in one day. Practice takes time and if you rush, you won’t remember anything.

A. Go through what you have been learning.

B. Mark your practice tests.

C. As long as you remain focused on the main topics, you will be able to do well on the test.

D. However, even the worst test performance could be turned around into a successful attempt.

E. It can be difficult to remember the material and understand which points to study.

F. You will notice them every day and reviewing won’t seem to be boring or dull.

G. Ask your teacher to summarize the topic with all the important points.

查看答案和解析>>

科目:高中英語 來源:廣東省廣州市2017屆英語高考沖刺題(二) 題型:完形填空

My family spent one summer vacation enjoying the beaches of beautiful Gulf Shores, Alabama. We bought a boat thinking this would make for a really ______ day at the beach for my two little girls.

I probably became too ______ with my younger daughter on the sand. When I looked up I became ______. The little boat with my older daughter in it had ______ far out from the shore. I called to her to come in ______ to shore and, although she seemed frightened, she was doing all she could to ______ just that. But there were no oars (槳) and her little ______ were too short to reach across the boat and into the ______.

Others on the beach seemed to be doing nothing to help except ______. I was standing as far out ______ the water as I could — ______ instructions to her, but with no ______. At last I thought to myself, “I know I’m a ______ swimmer but my daughter needs my help. I have no

____.” I jumped into the water.

At first my arms started moving very ______. I couldn’t believe I was doing this. I swam until I was breathless. I just kept hoping and ______ her. Finally, I reached the edge of the

____, grabbed the rope and began making my way back to shore. My child was crying so I tried

____ her, even though everything inside me was _______.

My life was forever changed by that ______. I learned if I believe in myself and dive right in I will have all the strength I need.

1.A. lucky B. fun C. moving D. peaceful

2.A. busy B. patient C. angry D. pleased

3.A. excited B. angry C. concerned D. amused

4.A. sunk B. stayed C. lost D. moved

5.A. closer B. faster C. earlier D. safer

6.A. avoid B. accomplish C. claim D. behave

7.A. legs B. fingers C. arms D. clothes

8.A. water B. shore C. board D. sand

9.A. applauding B. noticing C. swimming D. watching

10.A. off B. among C. in D. on

11.A. reading B. taking C. following D. shouting

12.A. hope B. reason C. end D. success

13.A. skillful B. poor C. brave D. new

14.A. choice B. way C. reason D. support

15.A. gently B. slowly C. confidently D. casually

16.A. keeping an eye on B. getting in touch with C. looking back at D. waving over to

17.A. strength B. oar C. boat D. beach

18.A. scolding B. calming C. praising D. helping

19.A. overjoyed B. changed C. missing D. trembling

20.A. point B. story C. experience D. scene

查看答案和解析>>

科目:高中英語 來源:黑龍江省哈爾濱市2017屆高三下學(xué)期第四次模擬考試英語試卷 題型:短文改錯

假定英語課上英語老師要求同桌之間互相修改作文,請你修改你同桌的以下作文。

文中共有10處語言錯誤,每句中最多有兩處。錯誤涉及一個單詞的增加、刪除或修改。

刪除:把多余的詞用斜線(\)劃掉。

增加:在缺詞處加一個漏字符號(∧),并在該詞下面寫出該加的詞。

修改:在錯的詞下劃一橫線,在該詞下面寫出修改后的詞。

注意:1、每處錯誤及修改均僅限一詞。

2、只允許修改10處,多者(從11處起)不計分。

Dear friends,

It is a great honor to share with you my experience in making English speeches.

To tell a truth, my spoken English used to be a big headache for me. Due to my terrible pronunciation, I often got misunderstood or even laughed by others. I never succeed in speech competitions. Therefore, I refused to give up. Every day I spent two hours listen to English programs to improve my oral skills. To my joy, my effort was finally paid off. I made steadily progress and managed to win prizes in some speech competition.

So problems can help us grow if we deal with it bravely and properly. This is which I've learned from my experience.

查看答案和解析>>

科目:高中英語 來源:2017屆高三英語收官沖刺教學(xué)質(zhì)量檢測2 題型:短文填空

All of us have read thrilling stories. In many of 1. (they) the hero had only a 2. (limit) and specified time to live. Sometimes it was as long as a year; sometimes as short as twenty-four hours, 3. we were always interested in 4. (discover) just how the dying man chose to spend his last days or his last hours.

Such stories set up thinking, wondering 5. we should do under similar circumstances. What 6. (happy) should we find in reviewing the past, and what regrets? Sometimes, I have thought it would be an excellent rule to live each day 7. if we should die tomorrow. Such an attitude would stress 8. (sharp) the values of life.

I have often thought it would be a blessing if each human being 9. (be) stricken blind and deaf for a few of days at some time during his early adult life. Darkness would make him 10. (much) appreciative of sight; silence would teach him the joys of sound.

查看答案和解析>>

科目:高中英語 來源:江西省2017屆高三全真模擬英語試卷 題型:書面表達(dá)

假定你是李華,你要完成一項關(guān)于中英學(xué)生寒假生活的調(diào)查。請給你的英國筆友Bill寫一封信,交流相關(guān)信息。要點(diǎn)如下:

1.寫信的原因;

2.介紹中國學(xué)生的寒假生活;

(1)時長:約20天

(2)活動

3.詢問英國學(xué)生的寒假生活。

注意:1.詞數(shù)100左右;

2.可以適當(dāng)增加細(xì)節(jié),以使行文連貫。

3. 信的開頭和結(jié)尾已給出, 不計入總詞數(shù)。

Dear Bill,

____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________

_______________________________________________________________

Yours sincerely,

Li Hua

查看答案和解析>>

科目:高中英語 來源:2017年高考英語考前《考試大綱》調(diào)研卷6 題型:閱讀理解

The National Parks and Federal Recreational Lands Pass Series

A pass is your ticket to more than 2,000 federal recreation sites. Each pass covers entrance fees at national parks and national wildlife refuges as well as standard amenity(便利設(shè)施)fees and day use fees for a driver and all passengers in a personal vehicle at per vehicle fee areas at national forests and grasslands, and at lands managed by the Bureau of Land Management, Bureau of Reclamation and U. S. Army Corps of Engineers. Children aged 15 or under are admitted free. The following passes make up the series:

Annual Pass

● $ 80

● Available to everyone.

● Can be obtained in person at a federal recreation site, right here online, or contact us.

● Non-transferable(不可轉(zhuǎn)讓的).

Senior Pass

● $ 10, lifetime pass

● For U. S. citizens or permanent residents aged 62 or over.

● May be obtained online, in person at a federal recreation site or through the mail using this application form. Applicants must provide documentation of age and residency or citizenship.

Access Pass

● Free

● For U. S. citizens or permanent residents with permanent disabilities.

● May be obtained in person at a federal recreation site or through the mail using this application form. Applicants must provide documentation of permanent disability and residency or citizenship.

Volunteer Pass

● Free

● For volunteers who acquire 250 service hours with the federal agencies that participate in the Interagency Pass Program.

● Contact your local federal recreation site for more information about volunteer opportunities or visit Volunteer, gov.

1.Which pass is suitable for a healthy U. S. citizen in his seventies?

A. Annual Pass. B. Senior Pass.

C. Access Pass. D. Volunteer Pass.

2.What do we know about the pass series?

A. Only U. S. citizens can access the series.

B. Ownership of Annual Pass can be handed over.

C. Access Pass can be got through two ways.

D. Volunteering guarantees Volunteer Pass.

3.Where is the passage probably taken from?

A. A report. B. A poster.

C. A newspaper. D. A webpage.

查看答案和解析>>

科目:高中英語 來源:2016-2017學(xué)年安徽省黃山市高二下學(xué)期期中考試英語試卷(解析版) 題型:完形填空

Animals are a great way to combat the struggles experienced by many people suffering from a mental illness, especially depression.

Having a pet is a big responsibility but it is_______ these responsibilities that we develop a relationship with the _______, just like children, become accustomed to routines. They become_______them and can oftentimes lose their cool if the routine is _______. Once a routine of care is established, nurturing(養(yǎng)育)our pet becomes second _______. In learning to care for our animals we ________routines for ourselves. It may _______deciding when the dog will be_______for a walk, but then we have to fit in shopping, getting to the gym, etc. based on the _______we have left. Having a routine gives us a sense of ________that we often feel gets lost when suffering from a mental health illness.

________we nurture and care for our pet, we simultaneously nurture and care for ourselves. ________, having a dog will get you outside, walking, running or just being ________. Exercise has time and time again been shown to help with depression and other ________ illnesses. It can be ________ to convince ourselves to get up for a walk simply to make ourselves feel better, but when we have a(n) ________to our pets we are more likely to do it.

While owning a pet is no ________task, the benefits can seriously outweigh the ________. If you are struggling with your mental illness, keeping a pet might just ________. Imagine the love when you feel when arriving home to see your dog waiting ________at the door. Not only do we love and care for our pets, they unconditionally love us as well.

1.A. from B. under C. through D. towards

2.A. child B. animal C. owner D. illness

3.A. tired of B. interested in C. dependent on D. worried about

4.A. found B. followed C. understood D. broken

5.A. task B. nature C. life D. thought

6.A. change B. give up C. create D. show off

7.A. start with B. finish C. deal with D. avoid

8.A. allowed B. carried C. asked D. taken

9.A. time B. money C. energy D. thing

10.A. control B. anxiety C. pride D. guilt

11.A. Since B. Unless C. As D. Though

12.A. As a result B. In addition C. After all D. For example

13.A. healthy B. active C. quiet D. happy

14.A. mental B. serious C. normal D. physical

15.A. fun B. confusing C. hard D. reasonable

16.A. attitude B. promise C. attention D. responsibility

17.A. simple B. great C. usual D. important

18.A. purpose B. effects C. costs D. results

19.A. help B. stop C. see D. try

20.A. nervously B. patiently C. aimlessly D. hurriedly

查看答案和解析>>

同步練習(xí)冊答案