what are they
1.) input devices2.) output devices3.) processing devices can you answer all of them .

1) Input devices are any devices that input information to the computer - Examples include your keyboard, mouse, microphone, ect.

2) Output devices are any devices that output information from the computer. - Examples include your monitor, printer, headset/speakers, ect.

3) Processing devices are devices that take the information and process it. The most obvious example of this is the Central Processing Unit (CPU) on your computer.

B, it is easy to scan for key information. there are times when a lot of information is included in a business letter. the block letter format you find key bits of information quickly, without having to read through the whole paper.