1. Introduction

Do you know what satellite TV, bar coding, joystick controllers, smoke detectors, laptop computers, translucent braces and portable cordless power tools have in common? Well, they are all spin-offs from NASA space programmes. Most of us come across these devices in our everyday lives without even knowing this. Unit 2a uses this context to revise and consolidate the use of the passive voice and some phrases used to describe a function.

 

Contents:

The Present Simple and Past Passive: Velcro was invented in 1948.

Describing a function: be used to.../for... -ing/in... The function of... is...:

  • This fabric is used to protect astronauts from fire.                         (to-infinitive)
  • This fabric is used for protecting astronauts from fire.                 (for + -ing verb form)
  • This fabric is used in space suits.                                                    (in + a noun)
  • The function of this fabric is to protect astronauts from fire.     (to-infinitive)
  • The function of this fabric is protecting astronauts from fire.   (-ing verb form)