HAVING A LONG AND HEALTHY LIFE

In the following link you have a listening exercise  about the secrets of having a long and healthy life:
http://www.elllo.org/english/0951/T992-Monica-LongLife.htm
You should llisten to it without reading, and then do the comprehension questions on the right

MODALS OF OBLIGATION

REMEMBER!

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Must: moral obligation.
Mustn't: (moral) prohibition.
Can: ability, possibility, or permission.
Can't: inability, impossibility, or no permission.
Have to: external obligation.
Don't have to: it's not necessary.
Should / shouldn't: advice or suggestion.

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MUST
http://www.englishgrammarsecrets.com/musthaveto/exercise2.html

MUST, MUSTN'T, CAN
http://www.englishexercises.org/makeagame/viewgame.asp?id=3341#a

MUST/HAVE TO

http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-49540.php

http://mbonillo.xavierre.com/exercises/eso4/4eso2007/musthaveto1.htm

HAVE TO/DON'T HAVE TO/MUSTN'T
http://www.eclecticenglish.com/grammar/HaveTo1A.html

http://www.englishgrammarsecrets.com/musthaveto/exercise7.html

Note: sentence 6. The answers provided by the site's self-correction do not make much sense, and all in all the sentence is not a very good example of natural language usage. My advice is  ignore that sentence and continue with the rest.

SHOULD/SHOULDN'T
http://www.englishexercises.org/makeagame/viewgame.asp?id=2865#a

MUST/MUSTN'T/SHOULD/ HAVE TO/DON'T HAVE TO/CAN/CAN'T
http://www.englishexercises.org/makeagame/viewgame.asp?id=3401

Note:
there is a mistake in the first sentence . According to the web site's self-correction, the answer is "shouldn't," but the correct answer is "should."

http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-87468.php

TENSE REVISION

http://www.englishexercises.org/makeagame/viewgame.asp?id=3636

http://www.impact-english.com/members/Grammar_Practice/Always/BS-Beg-gram-quiz.htm

http://www.english-room.com/waswere.htm

PRESENT PERFECT

Here you have some links for further practice on Present Perfect:

AFFIRMATIVE

http://www.englisch-hilfen.de/en/exercises/tenses/present_perfect_statements.htm
http://www.ego4u.com/en/cram-up/grammar/present-perfect-simple/exercises
http://www.really-learn-english.com/present-perfect-exercises.html#01

INTERROGATIVE

www.englishexercises.org/makeagame/viewgame.asp?id=5234
http://www.ego4u.com/en/cram-up/grammar/present-perfect-simple/exercises?08
http://www.englisch-hilfen.de/en/exercises/questions/present_perfect.htm

NEGATIVE
http://www.ego4u.com/en/cram-up/grammar/present-perfect-simple/exercises?05
http://www.englisch-hilfen.de/en/exercises/tenses/present_perfect_negation.htm

YET/JUST/ALREADY
http://www.esl-lounge.com/student/grammar/2g7-just-yet-already.php
http://www.servator.cat/eva/index_files/Grammar/2ndcycle/4tESO/prsperf2.htm
http://eslzone1.tripod.com/grammarinter/_yet.htm