Questions

The description of a data base is called the database schema , which is specified during database design and is not expected to change frequently . A displayed schema is called schema diagram .We call each object in the schema as schema construct.

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.

International Day for Disaster Reduction, held every 13 October, celebrates how people and communities around the world are reducing their exposure to disasters.

The year 2017 focus is : Reducing the number of affected people by disasters by 2030.