Asocial contract is an agreement between?
a. a government and its citizens.
b. citizens of two different countries.
c. governments of two different countries.
d. property owners and government.

   A. A government and its citizens

Explanation:  The social contract, as one of the achievements of the Enlightenment, constitutes an official agreement between the government and its citizens, by which the government acts in the interest of the citizens, protects their natural rights, and that same government is elected by the citizens by democratic means, that is, the rule of the majority. If the government does not work well in the interests of citizens, it can be changed, because its basic task is that all those who give their trust to the state can enjoy guaranteed natural rights, life, freedom, property. Like any contract, this has two contracting parties, so citizens have not only rights, but also the obligation to renounce some of their individual rights, when necessary, for the protection and interest of the state.

the of atp are the key to its ability to store and supply energy;

phosphate

the phosphate groups of atp are the key to its ability to store and supply energy. atp releases energy when it breaks bonds between its phosphate groups.