Although it is difficult to (7.come up with a rigorous set of criteria to evaluate how good an idea is, many drivers would agree that satellite navigation (8)systems (sat navs) are indispensable. l'd have bought one years ago if I’d realized how brilliant they were. It has transformed my (9)driving and taken all the stress away. You just (10) type in the correct post code and the sat nav guides you to your (11)destination. The (12) road spoken aloud prevent you from getting lost. It’s a great concept. Satellite navigation was originally used for military (13) applications such as the delivery of weapons and the tracking of troops. These days, the technology is used by pilots, sailors, explorers and taxi drivers. And, from my point of view, the best thing is that my wife isn’t going to say to me: “lf you’d brought a map, we wouldn’t be (14) lost now.”