It is a really good book for you study English. In this book you can study how to speak English and many grammatical points of English language which are very important.
This book is more than 40 mb, so it may take you a little long time to download. And the book is also designed for self-study. You can learn by yourself without any teachers to guide you because the book will be a teacher for you.
Learning business English can also be an advantage for you when you apply for a job in any company. These days working environment is diverse and complex. In such multidiverse culture, being flexibile can be a great opportunity for you to open a door for new life and career.
To learn business, you will have to pay a big amount of money if you go to business school or university. For those who do not have time and money this book will be a starting place for you to learn business English.
In conclusion, what I want to say is that this book will not give you a certificate to prove that you have proven knowledge of business. But you will know yourself that you improved a lot after you have studied this book.