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          The Chinese government _____ research into vaccine against H1N1for months, recently many have received
          the first doses. 

          A. is doing
          B. has done 
          C. had been doing 
          D. did 
          			
          

			
			
			
		
          



							
          
				相關(guān)習(xí)題
			
          	
						
          
			
          
				科目：高中英語
				來源：河南省期末題
				題型：單選題
			
          
									
          The Chinese government _____ research into vaccine against H1N1for months, recently many have received
          the first doses. 
          

          [     ]
          A. is doing
          B. has done 
          C. had been doing 
          D. did 
          

			
          
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