Question

1. what is a modem used for?

sending information to the hard disk
sending information over telephone lines
sending information to the cpu
sending information to the monitor

1. what information should always be on business communication of any kind?

subject
phone number
address
date

Explanation:

1. A modem is a device that modulates and demodulates signals. Its main function is to send information over telephone lines (in the case of traditional dial - up modems) or other communication channels (like cable or DSL lines). It is not used for sending information to the hard disk (that's the role of storage controllers), to the CPU (data transfer to CPU is via buses and interfaces within the computer), or to the monitor (handled by the graphics card and display interfaces).
2. In business communication, the date is crucial for record - keeping, legal purposes, and to establish the timeliness and sequence of communication. While a subject can help in organizing and understanding the communication, a phone number and address may not be relevant for all types of business communication (e.g., an internal memo within a company may not need an external address or phone number).

Answer:

1. sending information over telephone lines
2. Date