精选优质文档-倾情为你奉上Unmanned aerial vehicle is a kind of air craft which is controlled by soldiers on ground and doesnt need any pilots on board. With this obvious merit, it has attracted much attention of armies. Now, unmanned aerial vehicles are used to spy on enemies and to fight in war, but abuse of drones also incurs public protest. The main application of unmanned aerial vehicle is to spy on enemies. Many unmanned aerial vehicles are capable of cruising for days without being fuele