However, for explanation, it must obtain the Bescherelle "grammar" also very well designed too, simple and complete. Both are both independent and complementary.
I bought two books because they were recommended by my University. I do not regret it, these are the best books of grammar and exercises I have.
Level B2 is mainly the end of high school, beginning university studies (which allows to revise and deepen some points of grammar). But some exercises are easy (B1) (high school early to teaching in the first language).