ugh!..juussst b4 the exams started..i was like..artificial bloood?!..whats it called!?..n i couldnt find it in the books...but someone was like..PFC...n i was like..ohh right..whats PFC..perfluorocarbon??...n theyre like..cnt remember..n im like..oh well..ok...n then..in the exam i was...