Questions

The Opium Wars were two wars in the mid-19th century involving Anglo-Chinese disputes over British trade in China and China’s sovereignty. The disputes included the First Opium War (1839–1842) and the Second Opium War (1856–1860).

Two series alternate here, with every third number following a different pattern.
In the main series, 4 is added to each number to arrive the next.
In alternate series, 5 is subtracted from each number t arrive the next number.
Here in the main series 
3 + 4 = 7
7 + 4 = 11
11 + 4 = 15
15 + 4 = 19

In alternate series 
24 - 5 = 19
19 - 5 = 14...

We know that, preceeded means to come before. 

Hence, the given sentence, preceded in death means that person had died before this person.

For example :: Rahul preceeded Ravi in death, means Rahul died before Ravi.

Volatile memory is computer memory that requires power to maintain the stored information. It is a temporary memeory which cannot contain information permanently.

Example :: RAM or Random Access Memory

In short, Democracy is a government "of the people, by the people, and for the people."

Definition :

Democracy "is government by the people in which the supreme power is vested in the people and exercised directly by them or by their elected agents under a free electoral system." 

The conditions of a democratic election are:

* Every citizen should have one vote ad every vote should have an equal value.

* Voters choose from the political parties and candidates should be free to contest elections giving the voters a real choice.

* Elections should be held at regular intervals.

* The candidate preferred by the people should get elected.

* Elections should be conducted in free and fair manner where people can choose as they really wish.

The pharynx is a passageway shared by both food and air.