EJERCICIOS

http://www.englishexercises.org/makeagame/viewgame.asp?id=1972

http://www.englishexercises.org/makeagame/viewgame.asp?id=1973

http://www.members.iinet.net.au/~adelegc/grammar/present_simple/pres_sim_quests1.html

http://saberingles.com.ar/curso/lesson02/06.html

http://www.angelfire.com/on/topfen/testsdoesnt4.html  DON`T - DOESN´T

http://www.kico4u.de/english/uebungen/5klasse/doinneg.htm  DON`T - DOESN´T

http://www.englishexercises.org/makeagame/viewgame.asp?id=933 DO - DOES - DON`T - DOESN´T

http://www.members.iinet.net.au/~adelegc/grammar/present_simple/short_answers.html