Do you know any alternative, or contrasting, symptoms in humans? Give examples.

Alternative signs are mutually exclusive discrete signs that usually cannot be present in the body at the same time (for example, brown or blue eyes, black or white hair).

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.