By its 4 pin socket. ;) Hope this helps!
It is true because it is really a good practise to save a presentation before printing it
A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large industrial control systems which are used for controlling processes or machines.
Answer:
Electronic mail is a method of exchanging messages between people using electronic devices. Email entered limited use in the 1960s, but users could only send to users of the same computer, and some early email systems required the author and the recipient to both be online simultaneously, similar to instant messaging.
