What are ways signals can interact?

Which of the following is a way the operating system prevents unknown or unauthorized users from accessing the system?

1.the index finger on your right hand types the f r v 4 j u m 7 h y 6 n lo.9 j u 7 m g t 5 b 2.if you need to multiply 400, 2, and 1 ½, what would you type on the numeric keypad? 400*2*1.5 400/2*1.5 400/2/1.5 400*2*1½ 3.select all examples of proper keyboarding technique. rest your fingers gently on the home row or home keys. slouch in your chair. rest your palms on the keyboard. relax your fingers. keep your hands lower than your elbows.

Octothorpe is another name for what common computer keyboard symbol?