Questions

Black  surfaces are good emitters of heat ( They are also good absorbers of heat). If the black surface is rough too, the emitting will be better. So (b) is the correct answer. Shining surfaces reflect back radiation. So if the black surface is also shining the effectiveness of emitting heat is lessened.

The Civil Rights Movement :

The Civil Rights Movement in the United States was a struggle by black Americans to gain full citizenship rights and achieve racial equality.

Individuals and organizations challenged discrimination with a variety of activities, including protest marches, boycotts, and refusal to abide by segregation laws.

Many believe that the movement began with the bus boycott in Montgomery, Alabama, in 1955 and ended with the Voting Rights Act of 1965.

It is the protocol the routers in neighboring autonomous systems use to identify the set of networks that can be reached within or via each autonomous system.