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Choose an acceptable verb form from the two given in brackets according to the standard of formal writing. 1.( ) 2.( ) 3.( ) 4.( ) 5.( ) 6.( ) 7.( ) 8.( ) 9.( ) 10.( ) 11.( ) 12.( ) 13.( ) 14.( ) 15.( ) 16.( ) 17.( ) 18.( ) 19.( ) 20.( ) 21.( ) 22.( ) 23.( ) 24.( ) 25.( ) 26.( ) 27.( ) 28.( ) 29.( ) 30.( )