Teacher, I had to get up to date in this area and I have to admit that the book is very well done! Before an officer in the framework of a "DIF" for an adult (Senior frame), I think I found there a powerful working tool! To be continued ... Excellent book therefore to use, I currently use with an adult (not the one intended) Senior frame and also has an "old DIF" lessons are well done and the CD with exercises and other holes is also very convenient! I recommend without moderation from still an intermediate level and for someone who "washes" a bit already in business at European level or more! ...