Questions

The kidneys are stimulated to produce renin by a decrease in the blood pressure.

The renin-angiotensin system or RAS regulates blood pressure and fluid balance in the body. When blood volume or sodium levels in the body are low, or blood potassium is high, cells in the kidney release the enzyme, renin. Renin's primary function is therefore to eventually cause an increase in blood pressure, leading to restoration of perfusion pressure in the kidneys.

The "aha!" experience is known as insight learning.

Raja Ram Mohan Roy, a social and educational reformer, was an idealist who contributed immensely in eradicating social evils prevalent in the society during the 18th century.
He was popularly known as "Father of Modern India".

He was given the title of Raja by the Mughal emperor Akbar Shah II in the year 1830 as he had gone to England as an envoy of the emperor.

The last line from the file "trial" would be read twice. To avoid this, ues:

       While ( fgets (str, 80, fp) ! = NULL)

               puts (str);

Pyrenees, a chief mountain in Europe, forms a part of the great mountain across Europe and Asia.

Accoustics is a subject deals with the Study of sound

Aesthetics is a Philosophy of fine arts

The science or art of flight is called Aeronautics

The science of soil management is called Agronomy.

Magma is injected into surrounding rock forming an igneous intrusive.

Actually it is a plutonic formation in which magma present beneath Earth surface deforms the shape of rocks present above it