Alright, so mass is a property of a physical body. During physical changes, such as acceleration, force, etc, the mass stays the same since we are not affecting its physical shape, just where it is physics wise. So yeah mass is conserved during a physical change.
(This is very confusing I'm bad at explaining things sorry)
Ask your teacher. Depending on what he/she wants, the teacher may or may not deduct points from your assignment. Good luck!
The answer would be C. Digestive
The <em />circulatory system <em>circulates</em> the blood and lymph throughout the body. The excretory system <em>excretes</em> the body wastes.
Zane may be diagnosed with major depressive disorder.
When a person is depressed, they are feeling low all the time. They are not really interested in anything, and spend a lot of time sleeping because they don't see a point in doing anything else. This is what Zane is experiencing due to his depression.