The digestive system facilitates excretion of wastes by eliminating wastes from the digestive tract. During the digestion process, after the nutrients in the food has been absorbed by the small intestine, the waste products in the food will be moved into the large intestine where it will be processed for elimination in the form of feces. <span />
Try to stay true to who you are and find a good reason as to why you should be a great leader such as if you are in any AP classes or if you have demonstrated good leadership skills in the past. And if everything else fails people like food so you could bake/cook something cool that's has to do with science. Good luck!
A frog gets rid of it's urine through the kidneys because the heart pumps blood throughout the body, the lungs are used to take in O2 molecules and gills are use to filter out the hydrogen in HO2 so they can breathe under water. However the kidneys are part of the waste disposal system (what makes us need trip to the bathroom ever now and then) therefore that is the answer.<span />