Because it is easier to have a chain of command established with the staff if only one person is the leader. Companies and corporations also save money in the practice of only having a single leader or "boss."
I don't know if that answer will exactly help. :)
The answer would be A because a virus is surrounded in a protein coat
1 - complete protein
2-Vegetables
3-??
4- ??
5- Vitamin A
6 - Sucrose
7- ??
8-??
9- Citrus Fruits
Research states that the brain is sensitive to the electromagnetic radiation from cell phones, and can even stimulate brain activity.
