E.S.O.: Can /have to/ must/ should

Log onto the following web site and do the exercises on must/have to/should/ can:
Easy:
http://www.tolearnenglish.com/exercises/exercise-english-1/exercise-english-96.php

http://www.tolearnenglish.com/exercises/exercise-english-1/exercise-english-33.php

Intermediate:
http://www.aulafacil.com/Ingejerc/Lecciones/Ejerc26.htm

http://www.learnenglishfeelgood.com/lefg1_mixedmodals1.html

http://www.smic.be/smic5022/obligation2.htm

http://www.tolearnenglish.com/exercises/exercise-english-1/exercise-english-33.php

Advanced:
http://english.baladre.org/sedaviwebfront/cancouldability.htm

http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-8242.php

http://www.esoeonline.org/main-index/index-exercises/grammarexs/adv/advmodals.htm


And on vocabulary related to health and illnesses:

http://www.esltower.com/VOCABSHEETS/health/health.html

Write any questions or comments you have for me in 'comentarios'