Resposta:

B - are they copying the exercise?

     they aren't copying the exercise

C - am i dancing a lot?

     i am not dancing a lot

D - are they sleeping?

     they aren't sleeping

E - are we studying english?

     we aren't studying english

F - are you listening to music?

    you aren't listening to music

G - is John swimming?

     John isn't swimming

H - is Lisa typing a letter?

     Lisa isn't typing a letter

I - are you doing your homework?

   you aren't doing your homework

J - is he drinking water?

    he isn't drinking water