Поставьте слова в скобках в правильную форму: Human beings are characterized

Поставьте слова в скобках в правильную форму:

Human beings are characterized not only by their ________ (intelligent) but by their _________ (able) to use technology to shape their environment. The ________ (discover) of how to use fire was one of the most important events in the history of our species and the ________ (invent) of the plough and the wheel were also significant _________ (develop). It is difficult to imagine what our __________ (civilize) would be like without technology