The answer is D. the curculitory system transports hormons.
B) is the correct answer. The flu virus does not have the same genetic makeup each year as with each individual it infects its rapidly mutating.
The answer is community. A community is a group of people living in the same place.
There is no element with one valence electron and six energy levels. Only two valence electrons and six energy levels.
Answer:
Calcium
Explanation:
A: Calcium is a group 2 element with two valence electrons. Therefore, it is very reactive and gives up electrons in chemical reactions. It is likely to react with an element with six valence electrons that “wants” to gain two electrons. This would be an element in group 6, such as oxygen.
Answer:
The circulatory system, also known as the cardiovascular system, is a simple loop which starts, and ends, with your heart. It is a closed system, meaning blood does not enter or leave the system during its journey from your heart to your body and back again.
Explanation: