radioactivity 

  1. 名詞
不可數名詞:(物質的)放射性, 放射現象
輻射線, 放射線

    
                        
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例句

                

                    
    
                                                    
  1. 
                                Much of the radioactivity had decayed by 1980.                            
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  2. 
                                Mark checked the radioactivity plats carefully.                            
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  3. 
                                It is this electron which is the " radioactivity ".                            
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  4. 
                                No significant amounts of radioactivity were found .                            
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                                The radioactivity will outlive the turtle by decades.                            
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