3. Complete each sentence by choosing from the following devices:touch screen, trackball, touchpad, webcam. 1. A webcam is a stationary device that works like a mouse turned upside down. You roll the ball with your hand to move the pointer on the screen.
2. Interactive Touchscreen аге used in museums, information centers and Internet kiosks. You use your finger to point directly to objects on the screen.
3. A trackball is used to send live video images via the Internet.
4. A touchpad is found on notebook PCs. You use it by pressing the sensitive pad with a finger.
4. Read the text and complete this sentences with the correct ‘mouse action’.
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 I-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.
To start a program or open a document you double-click on its icon - that is, you rapidly press and release the mouse button twice.