On a class field trip, Zach took a walk through the woods using his senses. Zach made observations on the different sights, smells, and sounds in the woods. What system transferred the observations from his senses to his brain?

The questions have been asked in several important state and regional science exams in the United States. For example: TAKS-Texas Assessment of Knowledge and Skills, New York State Educational Department Regents exams, California Standards Test, etc.