The keyboard
A standard PC keyboard has various groups of keys. Alphanumeric keys - these represent letters and numbers, arranged as on a typewriter. A numeric keypad appears to the right of the main keyboard and contains numeric and editing keys; the Num Lock key is used to switch from numbers to editing functions. Function keys appear at the top of the keyboard and can be programmed to do special jobs. Cursor keys include 'arrow keys' which move the insertion point, and keys such as Home, End, Page Up, and Page Down, which let you move around documents.
Dedicated keys are used to issue commands or produce alternative characters. For example: Ctrl changes the functions of other keys (e.g. Ctrl + X cuts the selected text). Caps Lock sets the keyboard in 'CAPITALS' mode; it only affects letters. Enter (or Return) is pressed to select options from a menu or to start a new paragraph. Backspace deletes the character to the left of your current position.
The mouse
A mouse is a hand-held device that lets you move a pointer (or cursor) and select items on the screen. It has one or more buttons to communicate with the PC. A scroll wheel lets you move through your documents or web pages The pointer looks like an l-bar, an arrow or a pointing hand. An optical mouse has an optical sensor instead of a ball underneath. A cordless (wireless) mouse has no cable; it sends data via infrared signals or radio waves. Mouse actions:
to click, press and release the left button.
to double-click, press and release the left button twice.
to drag, hold down the button, move the pointer to a new place and then release the button.
to right-click, press and release the right button; this action displays a list of commands.
Voice input
Today you can also interact with your computer by voice with a voice-recognition system that converts voice into text, so you can dictate text directly onto your word processor or email program. You can also control your PC with voice commands; this means you can launch programs, open, save or print files. Some systems let you search the Web or chat using your voice instead of the keyboard.
Read the article and choose the appropriate heading for each paragraph from the given list: Function, Benefits, Size, Types, Features.
About scanners
Scanners are a type of computer hardware used to make digital prints of photos and documents, allowing users to print, copy or fax the material. A) __________
Scanners make a digital copy of a picture or a document. The digital copies can then be manipulated by the user and printed, copied or sent digitally anywhere in the world. Scanners are most often used by the general public to make copies of photos or important documents.
B) ___________
The width and depth of scanners has generally remained consistent at around 10 by 15 inches, simply because the scanner must accommodate full sheets of paper. The height has significantly decreased, however, and most mid-range scanners are now only around 1.5 to 3 inches tall. Depending on the size and quality standards, a scanner can weigh anywhere from 3 to 20 lbs.
C) ___________
They are identical in every scanner, with the only major difference being the quality of the digital copies they produce. Depending on how much money a person is willing to spend, some scanners can create near flawless photo-quality prints in no time at all. All scanners allow the user to scan in color or black and white. The quality of the scanned image can be adjusted depending on the need for higher quality or quicker completion.
D) ___________
You can print your own photos at home, preserve important documents with efficient, quality copies, scan images and documents in order to email or fax them to anyone in the world in just a matter of minutes.
E) ___________
There are basically two distinct categories: standalone scanners and those that are incorporated into a printer. While standalone scanners include only the scanner, they are often more powerful and thus capable of producing higher-quality scans. Scanners coupled with printers, however, provide more convenience, as they take up less space and often include one-touch scanning and printing, in which the push of a single button scans and image and prints a copy simultaneously. Most major computer hardware companies manufacture scanners of one kind or another; some of the most reliable and highly-rated include Canon, Hewlett-Packard, Epson and Dell.
(based on: http://www.ehow.com)