(A:An) optical disc drive (B:is) any storage device (C:what) uses light (D :to reading ) and write information. 

(a)  

On the back of the case there [are (A)] several [ports (B)] where many [peripherals (C)] such as a scanner, a printer… are [plug (D)] into.

(a)  

The touch screen [enable (A)] users to interact [directly (B)] with [what (C)] is displayed [with (D)] a stylus or one or more fingers.

(a)  

[A (A)]motherboard holds and [allow (B)] communication between [many (C)] electronic components [of (D)] a system.

(a)  

My brother often u (a)   (7) the antivirus software once a month.

S (a)   (7) are device which are used to convert electrical audio signals into a corresponding sound.

Every laptop has a b (a)   (6), which allows you to use the laptop when it’s not plugged in.

At t (a)   (7) is a part of the computer that lets you control the pointer by making a drawing motion with your finger.

Computer storage and memory is often m (a)   (6) in megabytes (MB) and gigabytes (GB).

You should inspect carefully before you o (a)   (6) any engine

Trojans, worms or spyware are all m (a)   (8) software that can damage to your system.

A f (a)   (9) website may look like an authentic one but has no contact details and will trick you to provide your sensitive information.

Your social networks are i (a)   (7) channels. Don’t use them to share confidential information

Last night, a hacker attachked our network and stole c (a)   (11) information such as: financial reports, trade secrets, etc.