Exam Preparation-from teacher’s desk

Exam Preparation-from teacher’s desk
Using the British corpus in exam preparation classes
Sounds fancy, doesn’t it? To put it simply, a corpus is a database of natural texts collected from writing and speech with the purpose of identifying patterns of authentic language usage. How does that apply to an exam preparation lesson?
The answer is pretty obvious, as a corpus keeps track of a variety of language usage in different contexts, namely registers. Intermediate and advanced students are expected to produce a range of texts (essays, emails, reviews, articles, stories, reports, proposals) by observing a number of criteria, including register.
So, what other better sources should they turned to if not the British corpus, a genuine linguistic treasure chest?