北师大版（2019）必修第一册《Unit 3 Celebrations Lesson 2-3》2021年同步练习卷

Ⅰ. 单句语法填空

• 1．We started out by exchanging

  （greet）but quickly moved on to business matters.
  组卷：1引用：4难度：0.6

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• 2．I'm sure you can deal with the problem

  （appropriate）.
  组卷：1引用：3难度：0.6

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• 3．I hope I can find a

  （suit） job after graduation.
  组卷：1引用：2难度：0.7

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• 4．How many countries are

  （represent） at the meeting？
  组卷：0引用：2难度：0.7

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• 5．They have

  （extend） the deadline by twenty-four hours.
  组卷：1引用：2难度：0.7

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• 6．

  （fortunate），he survived the earthquake.
  组卷：0引用：2难度：0.7

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• 7．His family then moved to a

  （slight） larger house．
  组卷：28引用：9难度：0.9

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III. 阅读理解

• 22．Researchers have solved a long-standing mystery：why rocks on a flat lakebed in Death Valley National Park in California sometimes move.Racetrack Playa，the waterless lakebed，is named for the long trails（痕迹） that the rocks，some of which weigh hundreds of pounds，leave in the earth.
     What was one of the world's natural wonders now appears to be the perfect combination of rain，wind，ice and sun，scientists have found.Dr Norris and James M Norris，a cousin and co-author，actually saw the rocks moving in December when they went to check on the project.
     For their study，they used special global positioning system tools，designed by James Norris，in rocks of various sizes brought from outside the park.They were not allowed to move or change anything of the existing playa（盐湖） stones.
     No river flows into the playa，though rainwater sometimes fills part of it to a depth of a few inches.It's when this happens，and the nights are below freezing and the days are fine，that the rocks may "sail"，the researchers said.On those occasions，the cold night air leaves a sheet（薄片）of ice only an eighth of an inch thick.Then the warmth of the sun causes the sheet to break up.As more ice melts（融化），some of these lesser sheets have room to move.Driven by light winds，the sheets push up against rocks.The wind drives the water，too，which also helps push the ice to some degree.The movement is slow，no more than about 15 feet a minute.
     The movements are episodic — the conditions may be just right for a few minutes，and then the sun causes more ice to break and the movement stops.And once the water disappears，it may be years before the rocks move again，even if the playa floods again，because the right temperature and wind conditions may not occur.
  
  （1）What do we know about Racetrack Playa？

  
  A．It has flat rocks in the earth.
  B．It is covered by rocks.
  C．It has some valleys.
  D．It is usually dry.
  （2）What was the park's attitude toward using GPS in the lakebed's stones？

  
  A．It doubted the method.
  B．It was against doing so.
  C．It felt it was worth a try.
  D．It thought it was useless.
  （3）Why do the stones "sail" according to the Norrises？

  
  A．They are moved by big floods.
  B．They move just because of strong winds.
  C．They are mainly pushed by wind-driven ice.
  D．They move very slowly on smooth ice sheets.
  （4）What does the underlined word "episodic" in the last paragraph probably mean？

  
  A．Amazingly big.
  B．Extremely slow.
  C．Happening sometimes.
  D．Going on without stopping.
  组卷：2引用：1难度：0.5

  解析

IV. 语法填空阅读下面短文， 在空白处填入1个适当的单词或括号内单词的正确形式。

• 23．More than twenty American states ban smoking in public.（1）

  study has proved that smoke-free laws can reduce a major effect of tobacco—heart disease.The study （2）

  （take）place in Pueblo，Colorado several years ago.In some states，there were 396 heart attack （3）

  （patient）in the year before the ban in hospitals.
      However，18 months （4）

  the ban，the number was 237.Smoking in enclosed（封闭的）places is very（5）

  （harm） to non-smokers.Adults may think they are（6）

  （actual）protecting their children from second-hand smoke when they smoke outside their homes，or when the children are not there.However，researchers（7）

  （warn）what they call "third-hand smoke" so far.When you smoke they say，dangerous matter from tobacco smoke gets into（8）

  （you） hair and clothing.Then，when you touch a baby，the baby comes into contact with that poisonous matter.The researchers also found that people，（9）

  agreed that smoke was bad for children's health，were more likely to have restriction on （10）

  （smoke） in their homes than others.
  组卷：19引用：3难度：0.5

  解析