Hi Thaddeush13,
Biases - " lacking a neutral viewpoint, or not having an open mind".
The potential biases that could hapen in this experiment are different intakes or types of coffee. For Example, Cold, Hot, Caramel. And each as a different size. Sugar intake is also another problem here.
I think tropical rainforests I could be wrong
Eat while you work. Having a healthy snack while you complete your homework, such as fruits or vegetables, can actually sharpen your focus and improve your memory.
Reward yourself for each task accomplished.
Think of the free time you will have to enjoy once your homework is complete.