<span>The main responsibility given to the Caliph in the first duty is to protect the entire faith of Islam, in a manner that represents the wishes of the very first Muslims. </span>
Answer:
a. mobile phones
Explanation:
One day some engineers decided to change the course of history. Thinking of a way to make communication more efficient and easy, they had the brilliant idea of creating a system that would be capable of communicating between cordless phones. The idea was not bad, but the technology of the time did not help much.
The real history of the mobile phone began in 1973, when the first call was made from a mobile phone to a landline. It was from April 1973 that all theories proved that the cell worked perfectly, and that the cell phone network suggested in 1947 was designed correctly. This was a not very well known moment, but it certainly was a fact marked forever because it was the moment that facilitated communication for most people through the creation of the mobile phone.
