It will help you  understand the role of each profession, which can be helpful when you have to select relevant information for the reader in the writing paper. By understanding the scope of each profession, it is easier to understand what would and wouldn’t be relevant to the reader. 

It will help you when taking your reading and listening papers as you will be  dealing with unknown or unfamiliar topics and vocabulary.  

You will also Build your vocabulary in context when reading around the 12 professions, making it easier to understand it when you come across these words in the exam.

Feeling prepared and confident that you are familiar with the 12 professions, can also help combat exam nerves when you sit your exam..