20．Have you seen my dog？I        for it and still haven't found it．（　　）
A．lookedB．was looking
C．have been lookingD．had been looking

分析 你看到我的狗了嗎？我一直在找它但仍然還沒有找到．

解答 答案：C．
根據(jù)句意"你看到我的狗了嗎？我一直在找它但仍然還沒有找到．"可知，look for這個(gè)動作已經(jīng)開始，一直延續(xù)到現(xiàn)在而且還將繼續(xù)延續(xù)下去，所以應(yīng)該用現(xiàn)在完成進(jìn)行時(shí)，故選C．

點(diǎn)評 本題考查時(shí)態(tài)．時(shí)態(tài)題關(guān)鍵在于對句意的理解，要根據(jù)上下文，找到符合語境的答案．

練習(xí)冊系列答案
相關(guān)習(xí)題

科目：高中英語 來源： 題型：填空題

13．A flying camera？Sounds （61）impossible（possible）？Well，think again because Nixie here will change your mind．
Nixie is a wearable camera．It is very tiny （62）in size and you can wear it on the wrist．It is amazing （63）that it flies and takes pictures and videos，and comes back to you when the work is done．
（64）The camera will be smart enough to identify you and the view．It will keep you in the frame and take some amazing shots．It can help you take pictures when you are climbing rocks，skating and （65）cycling （cycle）．It can also take midair photos or even videos when you are climbing （66）cliffs （cliff）or experiencing bungee jumping．It lets you （67）enjoy（enjoy）the moment rather than worrying about capturing （拍攝）it．
If Nixie ends up （68）winning（win）Intel's"Make it wearable"competition，the product is（69）expected（expect）to release within one year with a price tag of （70）less（little）than 1，000．

查看答案和解析>>

科目：高中英語 來源： 題型：選擇題

18．-Let's try to get two seats near the stage．
-Listen，we will be lucky enough ______ we can get any tickets．（　�。�
A．tillB．ifC．sinceD．though

查看答案和解析>>

科目：高中英語 來源： 題型：選擇題

8．It is too early to tell whether ________ the public expenses will benefit the company workers or not．（　�。�
A．cutting downB．cutting upC．cutting offD．cutting away

查看答案和解析>>

科目：高中英語 來源： 題型：閱讀理解

15．Two-thirds of the world's major rivers have now been disrupted（中斷）with more than 50，000 dams in an attempt to stole water and provide power．In the US，there are more than 85，000 dams，disrupting large and small rives，and in most cases transforming natural flow．The most famous of these，the Hoover Dam，constructed in the l930's，is mainly responsible for the fact that the Colorado River no longer reaches the ocean．
    Dams，besides all their attractive benefits，also have negative impacts．Creating a reservoir means a large area must be flooded．Communities may lose their land，houses and culturally impotent sites．
    Environmentally，the new reservoir can be a paradise for wildlife，especially birds．However，it can cause greenhouse gas emissions（排放）and poison the water for fish．Also，the dramatic rise and fall of water levels during dam releases is too extreme for plains and animals to cope with，resulting in dead zones around the shores of reservoirs．Fish that lay their eggs in the shallows，for example，may find a few hours later that those sites are high and dry．
    Dams don't just block water flow．They also prevent fish migrations，and are a barrier to sediment （沉淀物）flows．Instead of rushing downriver，sediments get backed up against the dam wall，which cause the reservoir level to increase over time．However，sediments which are rich in nutrients have become a problem．The fertility of the entire system can be influenced，with soils lost during seasonal rains not being replaced．
     Perhaps the biggest problem can be seen in deltas（三角洲），often host to large cities，which are sinking into the oceans．Groundwater is being extracted to feed the city，causing the urban weight to sink and sediments washed away by the ocean are no longer being replaced．The result is that sea level rise in cities from Shanghai to Alexandria．
51．What effects does creating a reservoir have on people's life？D
  a．People will see fewer birds near the rivers．
  b．Farmers below the dam may have less water to irrigate their fields
  c．Visitors can't see some cultural relics anymore．
  d．More conflicts and wars over water will break out
  e．More kinds of fish will become extinct in the future
  A．a(chǎn)，c    B．c，e    C．b，e   D．b，c
52．With many dams built across rivers，fish willB
  A．find more places to lay their eggs    B．face a more dangerous living habitat
  C．feed on more sediment rich in nutrients D．find it easier to deal with the rise of water
53．How can dams influence the cities like Shanghai？C
  A．Its entire system will be influenced．    B．The rainy season will last longer．
  C．It will lie below sea level in the future   D．Rich soils will be washed away
54．What does the text mainly talk about？A
  A．Environmental loss of dams．B．Cultural loss of dams
  C．Economical gain of dams      D．Environmental benefits of dams
55．Where can we most probably read this passage？C
    A．In a travel magazine     B．In a personal diary
    C．In a science report       D．In a biology textbook．

查看答案和解析>>

科目：高中英語 來源： 題型：閱讀理解

5．Hair has always been an important sign of beauty，especially true for women．Next to the face，hair is one of the main qualities people look for when they consider a woman's beauty． Whether long or short，curly or straight，hair often gets a lot of attention．
Each hair grows independently of other hairs．Not all hairs experience the same period of growth at the same time．During the period of active growth，which is called Anagen，hair grows at a rate of about or one centimeter a month．About eighty five percent of hair follicles（毛囊） are going through this process at any given time．This period can last from two to six years．
The Catagen period of hair growth comes next．It is then that hair growth begins to slow down．This period usually lasts two or three weeks．Finally，hair growth comes to a complete stop and the hairs begin to fall out．This period is known as Telogen．Once the Telogen period has ended，the hair growth process begins again．
So what happens when a person has trouble growing hair or suffers from hair loss？Your genes control how fast or how long your hair will grow．Some people have a longer than usual anagen growth period．These people may be able to grow more hair than the average person．
However，others struggle to grow shoulder length hair．These people have a shorter than normal anagen period．
Your health can also affect hair growth．Poor nutrition can cause some hair follicles to stop growing or cause the hairs that grow to become weak or thin．Problems with hair growth can result from thyroid problems or other conditions．Health experts say people who experience a sudden increase in hair loss should seek medical advice．

68．How many periods of hair growth are discussed in the passage？B   
    A．Two．          B．Three．           C．Four．          D．Five．
69．The Catagen period is a period thatD．
    A．the hairs start to fall out                   B．the hairs grow at a fast rate
    C．hair growth stops completely                  D．hair growth begins to slow down
70．What can be learned from the passage？C
    A．Hair grows no more after the Telogen period．
    B．One with shoulder length hair must grow more hair．
    C．Hair growth has much to do with nutrition and health．
    D．Only a few hair follicles go through the Anagen period．
71．What is suggested by health experts when one suffers from a sudden increase in hair loss？B
    A．Changing his genes．                     B．Going to see a doctor．
    C．Cutting all his hair off．               D．Eating more vegetables．

查看答案和解析>>

科目：高中英語 來源： 題型：選擇題

12．Many a person     up setting off firecrackers because of heavy smog．（　�。�
A．is givenB．has givenC．are givenD．have given

查看答案和解析>>

科目：高中英語 來源： 題型：選擇題

9．Look，the clothes ______ by the top fashion designer are so lovely．（　�。�
A．having designedB．designedC．designingD．being designed

查看答案和解析>>

科目：高中英語 來源： 題型：閱讀理解

19．A good education has always been highly valued in China，as the people believe that education ensures not only the future and development of the individual but also the family and the country as a whole．
Passed down from ancient times，the maxim from the Three-Character Scripture that says'if no proper education is given to children，their nature will go bad'has proved to be true．The great master Confucius taught us that'it is a pleasure to learn something and to try it out at intervals'．Similarly，numerous students have been convinced that'reading books excels all other careers'．The records tell us that Mencius'mother became an example to millions of mothers who were keen for their children to be talented．-she moved her home three times in order to choose a fine neighborhood in which Mencius could be effectively influenced．
21．The best title for this passage isB．
A．Statue of Confucius                  
B．Education in china     
C．Different education                  
D．The value in education
22．Why Chinese view education more much important than other things？C
A．Because it is a traditional thoughts and actions．
B．As it's a rule in China．
C．To development of the individual．
D．It's a trend in family education．
23．The underline word"excels"might meansC．
A．form         B．drag            C．outmatch          D．favorable．

查看答案和解析>>

同步練習(xí)冊答案