Questions

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.

A redox reaction is a type of reaction which involves transfer of electrons among two species. This reaction is also called oxidation-reduction reaction.

In oxidation process, there is an increase in oxidation state of an atom, ion or molecule by losing the electrons.

In reduction process, there is a decrease in oxidation state of an atom, ion or molecule by accepting the electrons.

1)

In this reaction, Ba undergoes oxidation and Cl undergoes reduction.
This reaction is redox reaction.
In this reaction, oxidation number of Ba increases from 0 to +2 . So, Ba undergoes oxidation. The oxidation number of Cl decreases from 0 to -1. So, Cl undergoes reduction.

2) 

From this above reaction, it is clear that Aluminum undergoes oxidation and silver undergoes reduction.
Due to this, this reaction is redox reaction.

In this reaction, oxidation number of Aluminum increases from 0 to +1. So, aluminum undergoes oxidation. The oxidation number of silver decreases from +1 to 0. So, silver undergoes reduction.

3)

In this reaction, Mg undergoes oxidation and Br undergoes reduction.
This reaction is redox reaction.
The reactions 1, 3 and 4 are redox reactions.
In this reaction, oxidation number of Mg increases from 0 to +2 . So, Mg undergoes oxidation. The oxidation number of Br decreases from 0 to -1 . So, Br undergoes reduction.

Hence all the above reactions are redox reactions.

Memory refresh is the process of periodically reading information from an area of computer memory and immediately rewriting the read information to the same area without modification, for the purpose of preserving the information.

Memory refresh is a background maintenance process required during the operation of semiconductor dynamic random-access memory (DRAM), the most widely used type of computer memory.

In the above given options, Retrovirus is the only virus which is not associated with cancer. Here the viruses which are associated with different types of cancer. They are:

Hepatitis virus which is associated with Liver cancer

Papillomavirus which is associated with Cervical cancer

Epstein-Barr virus which is associated with Burkitt's lymphoma.

Plants developing in dry conditions are called as xerophytes.