Preparation for Biology and Chemistry exams in secondary school, all levels by a Doctor of Science with five years of experience in preparing students for central jury exams in the French community. Courses given in French or English. "Straight to the point" method compatible with the widespread opinion among students that school is a prison from which you have to get out as quickly as possible by passing your exams. Nothing revolutionary, no great psycho-sociological ambitions: we start from the questions asked to the students during their interrogations and exams, we recall the theoretical bases necessary and sufficient to pass these tests. We systematically test learning to measure progress and assess the chances of passing future exams.