Energy flow can be defined
as the amount of energy that moves through a food chain and it flows through
ecosystem in one direction. Thus, the largest source of energy for an ecosystem
is the sun and the energy that enters the ecosystem is usually measured in
calories or joules.
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>