When DE-Oxygenated blood goes back into the heart, where does it
get pumped into next?

It depends on the subject for me. some exams are easier than others so i usually go through it and answer questions i know based on my general knowledge, then double check after. going through the lesson can a lot  because the exams can be  very lesson-specific, but sometimes they are ridiculously long so a lot of people don't take the time. i did find that, when i went through the lessons, i was making 100's on my exams vs strictly using + the internet and  i make 90's. 

It is good, unless you eat a lot of it. it contains sugar.

Some stress reducing strategies that a lot is: aromatherapy, yoga, meditation, quiet walks in the park, or listening to relaxing music.