Under the leadership of Mikhail Gorbachev, the doctrine of perestroika called for "<span>A. Openness in communication", since the "closed off" Soviet Tactics of the past were clearly not working by the 1980s.</span>
All you need to look through the human body systems you had in the unit and explain how they make you living, rather than dead. What body systems do you have that make you a living human being.
1. Your Cardiovascular system. It keeps your body and cells supplied with oxygen so they can stay alive.
2. Your nervous system. It allows your body to take outside stimuli and allow your brain to process and react to it.
3. Your Digestive system. It allows you to extract the energy from other living things and use it to power your body.
Answer:
circulatory and respiratory
Explanation:
The body system of Birds possesses a higher arrangement of organs to perform a particular function. The organs form a system which includes the organs and associated structures.
When the biologist observed the shortage of the dissolved oxygen and increase in the level of dissolved carbon dioxide, this could be the result of the failure of the circulatory system which supplies these gases on the body and the associated respiratory system which helps in the exchange of these gases with the atmosphere.
Thus, circulatory and respiratory is the correct answer.