Operating System (OS) is the answer.
An application runs in/on an OS. It is not the OS itself. Like Word or Chrome are applications.
Systems is too generic and not specific enough to mean anything in this context. Throw away answer.
Network Operating System does not 'usually' run on a hard drive but on memory chips in things like routers, wireless access points and switches that move network traffic.
Answer:
local Area Network, Wide Local Area Network and Personal Area Network
I would say 3-D model!!!! not 100% sure but this sounds most correct!
Answer:
If your cpu usage levels are greater than 90% during most of your work session, a faster CPU can greatly increase your computer's performance
Explanation:
CPU usage level is a good indicator for the computer performance.
Generally, computers use a low portion of their CPU power. When you open an application or listen to music on your computer, CPU usage level increases. After CPU intensive process ends, the CPU usage should drop to lower level again.
But if the CPU usage level is high all the time you use the computer, then it means that either there is a problem causing continuous CPU usage or your CPU is not fast enough. In the case of latter, you'd better to have a faster CPU.
It’s 12 because 3 times 4 is twelve, hope i helped!