ESO 3.Future Tenses: be going to, will.

These activities are useful for you to understand the differences between GOING TO and WILL:
http://www.englishexercises.org/makeagame/viewgame.asp?id=3135

More exercises about the contrast between GOING TO and WILL:
http://www.englishpage.com/verbpage/verbs18.htm
http://www.englishpage.com/verbpage/verbs20.htm

Practise the use of WILL and WON´T for future predictions in the context of global warming effects:

http://www.englishexercises.org/makeagame/viewgame.asp?id=7078