This idea of the impossible (became) even more relevant when we come to the individual, who might consider certain accomplishments impossible without realising that with persistent effort and determination they could be achieved.
Statement coverage is a white box test design technique which involves execution of all the executable statements in the source code at least once. It is used to calculate and measure the number of statements in the source code which can be executed given the requirements.
Optical fiber works on the principle of total internal reflection.
The Total Internal Reflection is the phenomenon in which the complete reflection of a light ray reaching an interface with a less dense medium when the angle of incidence exceeds the critical angle.