Questions

Government can be classified in three manners:

(1) who participates,

(2) geographic distribution of power, and

(3) legislative/executive relationship.

Who can participate is generally broken down into two forms of government,

democracy or dictatorship

While the legislative/executive relationship is broken down into

presidential or parliamentary

The geographic distribution of power is broken down into unitary, federal, and confederation (confederal).

Confederal System of Government ::

A system of government where power is located with the independent states and there is little power in the central government.

Today, no nation follows a confederal system. Organizations, like the European Union and the Commonwealth of Independent States, are based on the ideas of a confederal system. Several nations make up these organizations, but they still retain the majority of their independence.

In dealing with a coil spring the spring constant will depend on the stiffness of the spring material, the thicknessof the wire from which the spring is wound and, diameterof the turns of the coil, the number of turns per unit length and the overall length of the spring.

Sad means being unhappy, sorrowful, mournful, wistful,...

Hence, Somber means cheerless i.e, unhappy which is synonym of sad. All other options are opposites of Sad.

Iran is an important oil-producing region in the Middle East. Abadan on the Abadan island has one of the largest refineries in the world. 

Infrared radiation