Human beings are never satisfied.(1)________________.Human history is the history of inventions.An invention is something totally original,something that nobody else has thought of.It may be something physical,like a new machine,or it may be a new way of doing something,(2)_______________.The earliset inventions,like boats and weapons,were simple but effective ways of meeting basic need and were developed independently by people in different parts of the world who needed to travel or to hunt.(3)_____________________.If you come up with an original idea,the first thing to do is to register your invention at the Patent Office.It will be given a special number,which acts as a guarantee against anyone else stealing your idea.