Answer:
Sadness is caused when there is a strong emotional reaction to a particular object.
Sadness can sometimes lead to depression, but more commonly sadness can make you feel tired, angry, or stressed.
Explanation:
I think the relationship is Commensalism ( relationship between two organisms in which one benefits and the other does not benefit nor is harmed ) because the bird benefits and the cow does not benefit nor is harmed. Hope this helped ☺
Propagation is a form of asexual reproduction
Answer:
Your digestive system absorbs water and nutrients from the food you eat. Your circulatory system carries oxygen, water, and nutrients to cells throughout your body. Wastes from the cells are eliminated by your respiratory system, your excretory system, and your skin.
Explanation: